enable ya make for go projects

257 files changed, 28598 insertions, 0 deletions

diff --git a/contrib/go/_std_1.20/src/internal/abi/abi.go b/contrib/go/_std_1.20/src/internal/abi/abi.go
new file mode 100644
index 0000000000..11acac346f
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/abi/abi.go
@@ -0,0 +1,126 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package abi
+
+import (
+	"internal/goarch"
+	"unsafe"
+)
+
+// RegArgs is a struct that has space for each argument
+// and return value register on the current architecture.
+//
+// Assembly code knows the layout of the first two fields
+// of RegArgs.
+//
+// RegArgs also contains additional space to hold pointers
+// when it may not be safe to keep them only in the integer
+// register space otherwise.
+type RegArgs struct {
+	// Values in these slots should be precisely the bit-by-bit
+	// representation of how they would appear in a register.
+	//
+	// This means that on big endian arches, integer values should
+	// be in the top bits of the slot. Floats are usually just
+	// directly represented, but some architectures treat narrow
+	// width floating point values specially (e.g. they're promoted
+	// first, or they need to be NaN-boxed).
+	Ints   [IntArgRegs]uintptr  // untyped integer registers
+	Floats [FloatArgRegs]uint64 // untyped float registers
+
+	// Fields above this point are known to assembly.
+
+	// Ptrs is a space that duplicates Ints but with pointer type,
+	// used to make pointers passed or returned  in registers
+	// visible to the GC by making the type unsafe.Pointer.
+	Ptrs [IntArgRegs]unsafe.Pointer
+
+	// ReturnIsPtr is a bitmap that indicates which registers
+	// contain or will contain pointers on the return path from
+	// a reflectcall. The i'th bit indicates whether the i'th
+	// register contains or will contain a valid Go pointer.
+	ReturnIsPtr IntArgRegBitmap
+}
+
+func (r *RegArgs) Dump() {
+	print("Ints:")
+	for _, x := range r.Ints {
+		print(" ", x)
+	}
+	println()
+	print("Floats:")
+	for _, x := range r.Floats {
+		print(" ", x)
+	}
+	println()
+	print("Ptrs:")
+	for _, x := range r.Ptrs {
+		print(" ", x)
+	}
+	println()
+}
+
+// IntRegArgAddr returns a pointer inside of r.Ints[reg] that is appropriately
+// offset for an argument of size argSize.
+//
+// argSize must be non-zero, fit in a register, and a power-of-two.
+//
+// This method is a helper for dealing with the endianness of different CPU
+// architectures, since sub-word-sized arguments in big endian architectures
+// need to be "aligned" to the upper edge of the register to be interpreted
+// by the CPU correctly.
+func (r *RegArgs) IntRegArgAddr(reg int, argSize uintptr) unsafe.Pointer {
+	if argSize > goarch.PtrSize || argSize == 0 || argSize&(argSize-1) != 0 {
+		panic("invalid argSize")
+	}
+	offset := uintptr(0)
+	if goarch.BigEndian {
+		offset = goarch.PtrSize - argSize
+	}
+	return unsafe.Pointer(uintptr(unsafe.Pointer(&r.Ints[reg])) + offset)
+}
+
+// IntArgRegBitmap is a bitmap large enough to hold one bit per
+// integer argument/return register.
+type IntArgRegBitmap [(IntArgRegs + 7) / 8]uint8
+
+// Set sets the i'th bit of the bitmap to 1.
+func (b *IntArgRegBitmap) Set(i int) {
+	b[i/8] |= uint8(1) << (i % 8)
+}
+
+// Get returns whether the i'th bit of the bitmap is set.
+//
+// nosplit because it's called in extremely sensitive contexts, like
+// on the reflectcall return path.
+//
+//go:nosplit
+func (b *IntArgRegBitmap) Get(i int) bool {
+	return b[i/8]&(uint8(1)<<(i%8)) != 0
+}
+
+// FuncPC* intrinsics.
+//
+// CAREFUL: In programs with plugins, FuncPC* can return different values
+// for the same function (because there are actually multiple copies of
+// the same function in the address space). To be safe, don't use the
+// results of this function in any == expression. It is only safe to
+// use the result as an address at which to start executing code.
+
+// FuncPCABI0 returns the entry PC of the function f, which must be a
+// direct reference of a function defined as ABI0. Otherwise it is a
+// compile-time error.
+//
+// Implemented as a compile intrinsic.
+func FuncPCABI0(f any) uintptr
+
+// FuncPCABIInternal returns the entry PC of the function f. If f is a
+// direct reference of a function, it must be defined as ABIInternal.
+// Otherwise it is a compile-time error. If f is not a direct reference
+// of a defined function, it assumes that f is a func value. Otherwise
+// the behavior is undefined.
+//
+// Implemented as a compile intrinsic.
+func FuncPCABIInternal(f any) uintptr
diff --git a/contrib/go/_std_1.20/src/internal/abi/abi_amd64.go b/contrib/go/_std_1.20/src/internal/abi/abi_amd64.go
new file mode 100644
index 0000000000..d3c5678223
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/abi/abi_amd64.go
@@ -0,0 +1,18 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package abi
+
+const (
+	// See abi_generic.go.
+
+	// RAX, RBX, RCX, RDI, RSI, R8, R9, R10, R11.
+	IntArgRegs = 9
+
+	// X0 -> X14.
+	FloatArgRegs = 15
+
+	// We use SSE2 registers which support 64-bit float operations.
+	EffectiveFloatRegSize = 8
+)
diff --git a/contrib/go/_std_1.20/src/internal/abi/abi_arm64.go b/contrib/go/_std_1.20/src/internal/abi/abi_arm64.go
new file mode 100644
index 0000000000..4dc51431bf
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/abi/abi_arm64.go
@@ -0,0 +1,17 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package abi
+
+const (
+	// See abi_generic.go.
+
+	// R0 - R15.
+	IntArgRegs = 16
+
+	// F0 - F15.
+	FloatArgRegs = 16
+
+	EffectiveFloatRegSize = 8
+)
diff --git a/contrib/go/_std_1.20/src/internal/abi/abi_test.s b/contrib/go/_std_1.20/src/internal/abi/abi_test.s
new file mode 100644
index 0000000000..93ace3ef48
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/abi/abi_test.s
@@ -0,0 +1,27 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "textflag.h"
+
+#ifdef GOARCH_386
+#define PTRSIZE 4
+#endif
+#ifdef GOARCH_arm
+#define PTRSIZE 4
+#endif
+#ifdef GOARCH_mips
+#define PTRSIZE 4
+#endif
+#ifdef GOARCH_mipsle
+#define PTRSIZE 4
+#endif
+#ifndef PTRSIZE
+#define PTRSIZE 8
+#endif
+
+TEXT	internal∕abi·FuncPCTestFn(SB),NOSPLIT,$0-0
+	RET
+
+GLOBL	internal∕abi·FuncPCTestFnAddr(SB), NOPTR, $PTRSIZE
+DATA	internal∕abi·FuncPCTestFnAddr(SB)/PTRSIZE, $internal∕abi·FuncPCTestFn(SB)
diff --git a/contrib/go/_std_1.20/src/internal/abi/ya.make b/contrib/go/_std_1.20/src/internal/abi/ya.make
new file mode 100644
index 0000000000..640da81aac
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/abi/ya.make
@@ -0,0 +1,20 @@
+GO_LIBRARY()
+
+SRCS(
+    abi.go
+    abi_test.s
+)
+
+IF (ARCH_ARM64)
+    SRCS(
+        abi_arm64.go
+    )
+ENDIF()
+
+IF (ARCH_X86_64)
+    SRCS(
+        abi_amd64.go
+    )
+ENDIF()
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/buildcfg/cfg.go b/contrib/go/_std_1.20/src/internal/buildcfg/cfg.go
new file mode 100644
index 0000000000..a0736aaf74
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/buildcfg/cfg.go
@@ -0,0 +1,234 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package buildcfg provides access to the build configuration
+// described by the current environment. It is for use by build tools
+// such as cmd/go or cmd/compile and for setting up go/build's Default context.
+//
+// Note that it does NOT provide access to the build configuration used to
+// build the currently-running binary. For that, use runtime.GOOS etc
+// as well as internal/goexperiment.
+package buildcfg
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+)
+
+var (
+	GOROOT   = runtime.GOROOT() // cached for efficiency
+	GOARCH   = envOr("GOARCH", defaultGOARCH)
+	GOOS     = envOr("GOOS", defaultGOOS)
+	GO386    = envOr("GO386", defaultGO386)
+	GOAMD64  = goamd64()
+	GOARM    = goarm()
+	GOMIPS   = gomips()
+	GOMIPS64 = gomips64()
+	GOPPC64  = goppc64()
+	GOWASM   = gowasm()
+	ToolTags = toolTags()
+	GO_LDSO  = defaultGO_LDSO
+	Version  = version
+)
+
+// Error is one of the errors found (if any) in the build configuration.
+var Error error
+
+// Check exits the program with a fatal error if Error is non-nil.
+func Check() {
+	if Error != nil {
+		fmt.Fprintf(os.Stderr, "%s: %v\n", filepath.Base(os.Args[0]), Error)
+		os.Exit(2)
+	}
+}
+
+func envOr(key, value string) string {
+	if x := os.Getenv(key); x != "" {
+		return x
+	}
+	return value
+}
+
+func goamd64() int {
+	switch v := envOr("GOAMD64", defaultGOAMD64); v {
+	case "v1":
+		return 1
+	case "v2":
+		return 2
+	case "v3":
+		return 3
+	case "v4":
+		return 4
+	}
+	Error = fmt.Errorf("invalid GOAMD64: must be v1, v2, v3, v4")
+	return int(defaultGOAMD64[len("v")] - '0')
+}
+
+func goarm() int {
+	def := defaultGOARM
+	if GOOS == "android" && GOARCH == "arm" {
+		// Android arm devices always support GOARM=7.
+		def = "7"
+	}
+	switch v := envOr("GOARM", def); v {
+	case "5":
+		return 5
+	case "6":
+		return 6
+	case "7":
+		return 7
+	}
+	Error = fmt.Errorf("invalid GOARM: must be 5, 6, 7")
+	return int(def[0] - '0')
+}
+
+func gomips() string {
+	switch v := envOr("GOMIPS", defaultGOMIPS); v {
+	case "hardfloat", "softfloat":
+		return v
+	}
+	Error = fmt.Errorf("invalid GOMIPS: must be hardfloat, softfloat")
+	return defaultGOMIPS
+}
+
+func gomips64() string {
+	switch v := envOr("GOMIPS64", defaultGOMIPS64); v {
+	case "hardfloat", "softfloat":
+		return v
+	}
+	Error = fmt.Errorf("invalid GOMIPS64: must be hardfloat, softfloat")
+	return defaultGOMIPS64
+}
+
+func goppc64() int {
+	switch v := envOr("GOPPC64", defaultGOPPC64); v {
+	case "power8":
+		return 8
+	case "power9":
+		return 9
+	case "power10":
+		return 10
+	}
+	Error = fmt.Errorf("invalid GOPPC64: must be power8, power9, power10")
+	return int(defaultGOPPC64[len("power")] - '0')
+}
+
+type gowasmFeatures struct {
+	SatConv bool
+	SignExt bool
+}
+
+func (f gowasmFeatures) String() string {
+	var flags []string
+	if f.SatConv {
+		flags = append(flags, "satconv")
+	}
+	if f.SignExt {
+		flags = append(flags, "signext")
+	}
+	return strings.Join(flags, ",")
+}
+
+func gowasm() (f gowasmFeatures) {
+	for _, opt := range strings.Split(envOr("GOWASM", ""), ",") {
+		switch opt {
+		case "satconv":
+			f.SatConv = true
+		case "signext":
+			f.SignExt = true
+		case "":
+			// ignore
+		default:
+			Error = fmt.Errorf("invalid GOWASM: no such feature %q", opt)
+		}
+	}
+	return
+}
+
+func Getgoextlinkenabled() string {
+	return envOr("GO_EXTLINK_ENABLED", defaultGO_EXTLINK_ENABLED)
+}
+
+func toolTags() []string {
+	tags := experimentTags()
+	tags = append(tags, gogoarchTags()...)
+	return tags
+}
+
+func experimentTags() []string {
+	var list []string
+	// For each experiment that has been enabled in the toolchain, define a
+	// build tag with the same name but prefixed by "goexperiment." which can be
+	// used for compiling alternative files for the experiment. This allows
+	// changes for the experiment, like extra struct fields in the runtime,
+	// without affecting the base non-experiment code at all.
+	for _, exp := range Experiment.Enabled() {
+		list = append(list, "goexperiment."+exp)
+	}
+	return list
+}
+
+// GOGOARCH returns the name and value of the GO$GOARCH setting.
+// For example, if GOARCH is "amd64" it might return "GOAMD64", "v2".
+func GOGOARCH() (name, value string) {
+	switch GOARCH {
+	case "386":
+		return "GO386", GO386
+	case "amd64":
+		return "GOAMD64", fmt.Sprintf("v%d", GOAMD64)
+	case "arm":
+		return "GOARM", fmt.Sprintf("%d", GOARM)
+	case "mips", "mipsle":
+		return "GOMIPS", GOMIPS
+	case "mips64", "mips64le":
+		return "GOMIPS64", GOMIPS64
+	case "ppc64", "ppc64le":
+		return "GOPPC64", fmt.Sprintf("power%d", GOPPC64)
+	case "wasm":
+		return "GOWASM", GOWASM.String()
+	}
+	return "", ""
+}
+
+func gogoarchTags() []string {
+	switch GOARCH {
+	case "386":
+		return []string{GOARCH + "." + GO386}
+	case "amd64":
+		var list []string
+		for i := 1; i <= GOAMD64; i++ {
+			list = append(list, fmt.Sprintf("%s.v%d", GOARCH, i))
+		}
+		return list
+	case "arm":
+		var list []string
+		for i := 5; i <= GOARM; i++ {
+			list = append(list, fmt.Sprintf("%s.%d", GOARCH, i))
+		}
+		return list
+	case "mips", "mipsle":
+		return []string{GOARCH + "." + GOMIPS}
+	case "mips64", "mips64le":
+		return []string{GOARCH + "." + GOMIPS64}
+	case "ppc64", "ppc64le":
+		var list []string
+		for i := 8; i <= GOPPC64; i++ {
+			list = append(list, fmt.Sprintf("%s.power%d", GOARCH, i))
+		}
+		return list
+	case "wasm":
+		var list []string
+		if GOWASM.SatConv {
+			list = append(list, GOARCH+".satconv")
+		}
+		if GOWASM.SignExt {
+			list = append(list, GOARCH+".signext")
+		}
+		return list
+	}
+	return nil
+}
diff --git a/contrib/go/_std_1.20/src/internal/buildcfg/exp.go b/contrib/go/_std_1.20/src/internal/buildcfg/exp.go
new file mode 100644
index 0000000000..546a68d335
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/buildcfg/exp.go
@@ -0,0 +1,190 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package buildcfg
+
+import (
+	"fmt"
+	"internal/goexperiment"
+	"reflect"
+	"strings"
+)
+
+// ExperimentFlags represents a set of GOEXPERIMENT flags relative to a baseline
+// (platform-default) experiment configuration.
+type ExperimentFlags struct {
+	goexperiment.Flags
+	baseline goexperiment.Flags
+}
+
+// Experiment contains the toolchain experiments enabled for the
+// current build.
+//
+// (This is not necessarily the set of experiments the compiler itself
+// was built with.)
+//
+// experimentBaseline specifies the experiment flags that are enabled by
+// default in the current toolchain. This is, in effect, the "control"
+// configuration and any variation from this is an experiment.
+var Experiment ExperimentFlags = func() ExperimentFlags {
+	flags, err := ParseGOEXPERIMENT(GOOS, GOARCH, envOr("GOEXPERIMENT", defaultGOEXPERIMENT))
+	if err != nil {
+		Error = err
+		return ExperimentFlags{}
+	}
+	return *flags
+}()
+
+// DefaultGOEXPERIMENT is the embedded default GOEXPERIMENT string.
+// It is not guaranteed to be canonical.
+const DefaultGOEXPERIMENT = defaultGOEXPERIMENT
+
+// FramePointerEnabled enables the use of platform conventions for
+// saving frame pointers.
+//
+// This used to be an experiment, but now it's always enabled on
+// platforms that support it.
+//
+// Note: must agree with runtime.framepointer_enabled.
+var FramePointerEnabled = GOARCH == "amd64" || GOARCH == "arm64"
+
+// ParseGOEXPERIMENT parses a (GOOS, GOARCH, GOEXPERIMENT)
+// configuration tuple and returns the enabled and baseline experiment
+// flag sets.
+//
+// TODO(mdempsky): Move to internal/goexperiment.
+func ParseGOEXPERIMENT(goos, goarch, goexp string) (*ExperimentFlags, error) {
+	// regabiSupported is set to true on platforms where register ABI is
+	// supported and enabled by default.
+	// regabiAlwaysOn is set to true on platforms where register ABI is
+	// always on.
+	var regabiSupported, regabiAlwaysOn bool
+	switch goarch {
+	case "amd64", "arm64", "ppc64le", "ppc64", "riscv64":
+		regabiAlwaysOn = true
+		regabiSupported = true
+	}
+
+	baseline := goexperiment.Flags{
+		RegabiWrappers:   regabiSupported,
+		RegabiArgs:       regabiSupported,
+		Unified:          true,
+		CoverageRedesign: true,
+	}
+
+	// Start with the statically enabled set of experiments.
+	flags := &ExperimentFlags{
+		Flags:    baseline,
+		baseline: baseline,
+	}
+
+	// Pick up any changes to the baseline configuration from the
+	// GOEXPERIMENT environment. This can be set at make.bash time
+	// and overridden at build time.
+	if goexp != "" {
+		// Create a map of known experiment names.
+		names := make(map[string]func(bool))
+		rv := reflect.ValueOf(&flags.Flags).Elem()
+		rt := rv.Type()
+		for i := 0; i < rt.NumField(); i++ {
+			field := rv.Field(i)
+			names[strings.ToLower(rt.Field(i).Name)] = field.SetBool
+		}
+
+		// "regabi" is an alias for all working regabi
+		// subexperiments, and not an experiment itself. Doing
+		// this as an alias make both "regabi" and "noregabi"
+		// do the right thing.
+		names["regabi"] = func(v bool) {
+			flags.RegabiWrappers = v
+			flags.RegabiArgs = v
+		}
+
+		// Parse names.
+		for _, f := range strings.Split(goexp, ",") {
+			if f == "" {
+				continue
+			}
+			if f == "none" {
+				// GOEXPERIMENT=none disables all experiment flags.
+				// This is used by cmd/dist, which doesn't know how
+				// to build with any experiment flags.
+				flags.Flags = goexperiment.Flags{}
+				continue
+			}
+			val := true
+			if strings.HasPrefix(f, "no") {
+				f, val = f[2:], false
+			}
+			set, ok := names[f]
+			if !ok {
+				return nil, fmt.Errorf("unknown GOEXPERIMENT %s", f)
+			}
+			set(val)
+		}
+	}
+
+	if regabiAlwaysOn {
+		flags.RegabiWrappers = true
+		flags.RegabiArgs = true
+	}
+	// regabi is only supported on amd64, arm64, riscv64, ppc64 and ppc64le.
+	if !regabiSupported {
+		flags.RegabiWrappers = false
+		flags.RegabiArgs = false
+	}
+	// Check regabi dependencies.
+	if flags.RegabiArgs && !flags.RegabiWrappers {
+		return nil, fmt.Errorf("GOEXPERIMENT regabiargs requires regabiwrappers")
+	}
+	return flags, nil
+}
+
+// String returns the canonical GOEXPERIMENT string to enable this experiment
+// configuration. (Experiments in the same state as in the baseline are elided.)
+func (exp *ExperimentFlags) String() string {
+	return strings.Join(expList(&exp.Flags, &exp.baseline, false), ",")
+}
+
+// expList returns the list of lower-cased experiment names for
+// experiments that differ from base. base may be nil to indicate no
+// experiments. If all is true, then include all experiment flags,
+// regardless of base.
+func expList(exp, base *goexperiment.Flags, all bool) []string {
+	var list []string
+	rv := reflect.ValueOf(exp).Elem()
+	var rBase reflect.Value
+	if base != nil {
+		rBase = reflect.ValueOf(base).Elem()
+	}
+	rt := rv.Type()
+	for i := 0; i < rt.NumField(); i++ {
+		name := strings.ToLower(rt.Field(i).Name)
+		val := rv.Field(i).Bool()
+		baseVal := false
+		if base != nil {
+			baseVal = rBase.Field(i).Bool()
+		}
+		if all || val != baseVal {
+			if val {
+				list = append(list, name)
+			} else {
+				list = append(list, "no"+name)
+			}
+		}
+	}
+	return list
+}
+
+// Enabled returns a list of enabled experiments, as
+// lower-cased experiment names.
+func (exp *ExperimentFlags) Enabled() []string {
+	return expList(&exp.Flags, nil, false)
+}
+
+// All returns a list of all experiment settings.
+// Disabled experiments appear in the list prefixed by "no".
+func (exp *ExperimentFlags) All() []string {
+	return expList(&exp.Flags, nil, true)
+}
diff --git a/contrib/go/_std_1.20/src/internal/buildcfg/ya.make b/contrib/go/_std_1.20/src/internal/buildcfg/ya.make
new file mode 100644
index 0000000000..616e2ae44d
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/buildcfg/ya.make
@@ -0,0 +1,9 @@
+GO_LIBRARY()
+
+SRCS(
+    cfg.go
+    exp.go
+    zbootstrap.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/buildcfg/zbootstrap.go b/contrib/go/_std_1.20/src/internal/buildcfg/zbootstrap.go
new file mode 100644
index 0000000000..2035d68b60
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/buildcfg/zbootstrap.go
@@ -0,0 +1,18 @@
+// Code generated by go tool dist; DO NOT EDIT.
+
+package buildcfg
+
+import "runtime"
+
+const defaultGO386 = `sse2`
+const defaultGOAMD64 = `v1`
+const defaultGOARM = `5`
+const defaultGOMIPS = `hardfloat`
+const defaultGOMIPS64 = `hardfloat`
+const defaultGOPPC64 = `power8`
+const defaultGOEXPERIMENT = ``
+const defaultGO_EXTLINK_ENABLED = ``
+const defaultGO_LDSO = ``
+const version = `go1.20.4`
+const defaultGOOS = runtime.GOOS
+const defaultGOARCH = runtime.GOARCH
diff --git a/contrib/go/_std_1.20/src/internal/bytealg/bytealg.go b/contrib/go/_std_1.20/src/internal/bytealg/bytealg.go
new file mode 100644
index 0000000000..ebebce75fe
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/bytealg/bytealg.go
@@ -0,0 +1,150 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package bytealg
+
+import (
+	"internal/cpu"
+	"unsafe"
+)
+
+// Offsets into internal/cpu records for use in assembly.
+const (
+	offsetX86HasSSE42  = unsafe.Offsetof(cpu.X86.HasSSE42)
+	offsetX86HasAVX2   = unsafe.Offsetof(cpu.X86.HasAVX2)
+	offsetX86HasPOPCNT = unsafe.Offsetof(cpu.X86.HasPOPCNT)
+
+	offsetS390xHasVX = unsafe.Offsetof(cpu.S390X.HasVX)
+
+	offsetPPC64HasPOWER9 = unsafe.Offsetof(cpu.PPC64.IsPOWER9)
+)
+
+// MaxLen is the maximum length of the string to be searched for (argument b) in Index.
+// If MaxLen is not 0, make sure MaxLen >= 4.
+var MaxLen int
+
+// FIXME: the logic of HashStrBytes, HashStrRevBytes, IndexRabinKarpBytes and HashStr, HashStrRev,
+// IndexRabinKarp are exactly the same, except that the types are different. Can we eliminate
+// three of them without causing allocation?
+
+// PrimeRK is the prime base used in Rabin-Karp algorithm.
+const PrimeRK = 16777619
+
+// HashStrBytes returns the hash and the appropriate multiplicative
+// factor for use in Rabin-Karp algorithm.
+func HashStrBytes(sep []byte) (uint32, uint32) {
+	hash := uint32(0)
+	for i := 0; i < len(sep); i++ {
+		hash = hash*PrimeRK + uint32(sep[i])
+	}
+	var pow, sq uint32 = 1, PrimeRK
+	for i := len(sep); i > 0; i >>= 1 {
+		if i&1 != 0 {
+			pow *= sq
+		}
+		sq *= sq
+	}
+	return hash, pow
+}
+
+// HashStr returns the hash and the appropriate multiplicative
+// factor for use in Rabin-Karp algorithm.
+func HashStr(sep string) (uint32, uint32) {
+	hash := uint32(0)
+	for i := 0; i < len(sep); i++ {
+		hash = hash*PrimeRK + uint32(sep[i])
+	}
+	var pow, sq uint32 = 1, PrimeRK
+	for i := len(sep); i > 0; i >>= 1 {
+		if i&1 != 0 {
+			pow *= sq
+		}
+		sq *= sq
+	}
+	return hash, pow
+}
+
+// HashStrRevBytes returns the hash of the reverse of sep and the
+// appropriate multiplicative factor for use in Rabin-Karp algorithm.
+func HashStrRevBytes(sep []byte) (uint32, uint32) {
+	hash := uint32(0)
+	for i := len(sep) - 1; i >= 0; i-- {
+		hash = hash*PrimeRK + uint32(sep[i])
+	}
+	var pow, sq uint32 = 1, PrimeRK
+	for i := len(sep); i > 0; i >>= 1 {
+		if i&1 != 0 {
+			pow *= sq
+		}
+		sq *= sq
+	}
+	return hash, pow
+}
+
+// HashStrRev returns the hash of the reverse of sep and the
+// appropriate multiplicative factor for use in Rabin-Karp algorithm.
+func HashStrRev(sep string) (uint32, uint32) {
+	hash := uint32(0)
+	for i := len(sep) - 1; i >= 0; i-- {
+		hash = hash*PrimeRK + uint32(sep[i])
+	}
+	var pow, sq uint32 = 1, PrimeRK
+	for i := len(sep); i > 0; i >>= 1 {
+		if i&1 != 0 {
+			pow *= sq
+		}
+		sq *= sq
+	}
+	return hash, pow
+}
+
+// IndexRabinKarpBytes uses the Rabin-Karp search algorithm to return the index of the
+// first occurrence of substr in s, or -1 if not present.
+func IndexRabinKarpBytes(s, sep []byte) int {
+	// Rabin-Karp search
+	hashsep, pow := HashStrBytes(sep)
+	n := len(sep)
+	var h uint32
+	for i := 0; i < n; i++ {
+		h = h*PrimeRK + uint32(s[i])
+	}
+	if h == hashsep && Equal(s[:n], sep) {
+		return 0
+	}
+	for i := n; i < len(s); {
+		h *= PrimeRK
+		h += uint32(s[i])
+		h -= pow * uint32(s[i-n])
+		i++
+		if h == hashsep && Equal(s[i-n:i], sep) {
+			return i - n
+		}
+	}
+	return -1
+}
+
+// IndexRabinKarp uses the Rabin-Karp search algorithm to return the index of the
+// first occurrence of substr in s, or -1 if not present.
+func IndexRabinKarp(s, substr string) int {
+	// Rabin-Karp search
+	hashss, pow := HashStr(substr)
+	n := len(substr)
+	var h uint32
+	for i := 0; i < n; i++ {
+		h = h*PrimeRK + uint32(s[i])
+	}
+	if h == hashss && s[:n] == substr {
+		return 0
+	}
+	for i := n; i < len(s); {
+		h *= PrimeRK
+		h += uint32(s[i])
+		h -= pow * uint32(s[i-n])
+		i++
+		if h == hashss && s[i-n:i] == substr {
+			return i - n
+		}
+	}
+	return -1
+}
diff --git a/contrib/go/_std_1.20/src/internal/bytealg/compare_amd64.s b/contrib/go/_std_1.20/src/internal/bytealg/compare_amd64.s
new file mode 100644
index 0000000000..fdd015f560
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/bytealg/compare_amd64.s
@@ -0,0 +1,237 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "go_asm.h"
+#include "asm_amd64.h"
+#include "textflag.h"
+
+TEXT ·Compare<ABIInternal>(SB),NOSPLIT,$0-56
+	// AX = a_base (want in SI)
+	// BX = a_len  (want in BX)
+	// CX = a_cap  (unused)
+	// DI = b_base (want in DI)
+	// SI = b_len  (want in DX)
+	// R8 = b_cap  (unused)
+	MOVQ	SI, DX
+	MOVQ	AX, SI
+	JMP	cmpbody<>(SB)
+
+TEXT runtime·cmpstring<ABIInternal>(SB),NOSPLIT,$0-40
+	// AX = a_base (want in SI)
+	// BX = a_len  (want in BX)
+	// CX = b_base (want in DI)
+	// DI = b_len  (want in DX)
+	MOVQ	AX, SI
+	MOVQ	DI, DX
+	MOVQ	CX, DI
+	JMP	cmpbody<>(SB)
+
+// input:
+//   SI = a
+//   DI = b
+//   BX = alen
+//   DX = blen
+// output:
+//   AX = output (-1/0/1)
+TEXT cmpbody<>(SB),NOSPLIT,$0-0
+	CMPQ	SI, DI
+	JEQ	allsame
+	CMPQ	BX, DX
+	MOVQ	DX, R8
+	CMOVQLT	BX, R8 // R8 = min(alen, blen) = # of bytes to compare
+	CMPQ	R8, $8
+	JB	small
+
+	CMPQ	R8, $63
+	JBE	loop
+#ifndef hasAVX2
+	CMPB	internal∕cpu·X86+const_offsetX86HasAVX2(SB), $1
+	JEQ     big_loop_avx2
+	JMP	big_loop
+#else
+	JMP	big_loop_avx2
+#endif
+loop:
+	CMPQ	R8, $16
+	JBE	_0through16
+	MOVOU	(SI), X0
+	MOVOU	(DI), X1
+	PCMPEQB X0, X1
+	PMOVMSKB X1, AX
+	XORQ	$0xffff, AX	// convert EQ to NE
+	JNE	diff16	// branch if at least one byte is not equal
+	ADDQ	$16, SI
+	ADDQ	$16, DI
+	SUBQ	$16, R8
+	JMP	loop
+
+diff64:
+	ADDQ	$48, SI
+	ADDQ	$48, DI
+	JMP	diff16
+diff48:
+	ADDQ	$32, SI
+	ADDQ	$32, DI
+	JMP	diff16
+diff32:
+	ADDQ	$16, SI
+	ADDQ	$16, DI
+	// AX = bit mask of differences
+diff16:
+	BSFQ	AX, BX	// index of first byte that differs
+	XORQ	AX, AX
+	MOVB	(SI)(BX*1), CX
+	CMPB	CX, (DI)(BX*1)
+	SETHI	AX
+	LEAQ	-1(AX*2), AX	// convert 1/0 to +1/-1
+	RET
+
+	// 0 through 16 bytes left, alen>=8, blen>=8
+_0through16:
+	CMPQ	R8, $8
+	JBE	_0through8
+	MOVQ	(SI), AX
+	MOVQ	(DI), CX
+	CMPQ	AX, CX
+	JNE	diff8
+_0through8:
+	MOVQ	-8(SI)(R8*1), AX
+	MOVQ	-8(DI)(R8*1), CX
+	CMPQ	AX, CX
+	JEQ	allsame
+
+	// AX and CX contain parts of a and b that differ.
+diff8:
+	BSWAPQ	AX	// reverse order of bytes
+	BSWAPQ	CX
+	XORQ	AX, CX
+	BSRQ	CX, CX	// index of highest bit difference
+	SHRQ	CX, AX	// move a's bit to bottom
+	ANDQ	$1, AX	// mask bit
+	LEAQ	-1(AX*2), AX // 1/0 => +1/-1
+	RET
+
+	// 0-7 bytes in common
+small:
+	LEAQ	(R8*8), CX	// bytes left -> bits left
+	NEGQ	CX		//  - bits lift (== 64 - bits left mod 64)
+	JEQ	allsame
+
+	// load bytes of a into high bytes of AX
+	CMPB	SI, $0xf8
+	JA	si_high
+	MOVQ	(SI), SI
+	JMP	si_finish
+si_high:
+	MOVQ	-8(SI)(R8*1), SI
+	SHRQ	CX, SI
+si_finish:
+	SHLQ	CX, SI
+
+	// load bytes of b in to high bytes of BX
+	CMPB	DI, $0xf8
+	JA	di_high
+	MOVQ	(DI), DI
+	JMP	di_finish
+di_high:
+	MOVQ	-8(DI)(R8*1), DI
+	SHRQ	CX, DI
+di_finish:
+	SHLQ	CX, DI
+
+	BSWAPQ	SI	// reverse order of bytes
+	BSWAPQ	DI
+	XORQ	SI, DI	// find bit differences
+	JEQ	allsame
+	BSRQ	DI, CX	// index of highest bit difference
+	SHRQ	CX, SI	// move a's bit to bottom
+	ANDQ	$1, SI	// mask bit
+	LEAQ	-1(SI*2), AX // 1/0 => +1/-1
+	RET
+
+allsame:
+	XORQ	AX, AX
+	XORQ	CX, CX
+	CMPQ	BX, DX
+	SETGT	AX	// 1 if alen > blen
+	SETEQ	CX	// 1 if alen == blen
+	LEAQ	-1(CX)(AX*2), AX	// 1,0,-1 result
+	RET
+
+	// this works for >= 64 bytes of data.
+#ifndef hasAVX2
+big_loop:
+	MOVOU	(SI), X0
+	MOVOU	(DI), X1
+	PCMPEQB X0, X1
+	PMOVMSKB X1, AX
+	XORQ	$0xffff, AX
+	JNE	diff16
+
+	MOVOU	16(SI), X0
+	MOVOU	16(DI), X1
+	PCMPEQB X0, X1
+	PMOVMSKB X1, AX
+	XORQ	$0xffff, AX
+	JNE	diff32
+
+	MOVOU	32(SI), X0
+	MOVOU	32(DI), X1
+	PCMPEQB X0, X1
+	PMOVMSKB X1, AX
+	XORQ	$0xffff, AX
+	JNE	diff48
+
+	MOVOU	48(SI), X0
+	MOVOU	48(DI), X1
+	PCMPEQB X0, X1
+	PMOVMSKB X1, AX
+	XORQ	$0xffff, AX
+	JNE	diff64
+
+	ADDQ	$64, SI
+	ADDQ	$64, DI
+	SUBQ	$64, R8
+	CMPQ	R8, $64
+	JBE	loop
+	JMP	big_loop
+#endif
+
+	// Compare 64-bytes per loop iteration.
+	// Loop is unrolled and uses AVX2.
+big_loop_avx2:
+	VMOVDQU	(SI), Y2
+	VMOVDQU	(DI), Y3
+	VMOVDQU	32(SI), Y4
+	VMOVDQU	32(DI), Y5
+	VPCMPEQB Y2, Y3, Y0
+	VPMOVMSKB Y0, AX
+	XORL	$0xffffffff, AX
+	JNE	diff32_avx2
+	VPCMPEQB Y4, Y5, Y6
+	VPMOVMSKB Y6, AX
+	XORL	$0xffffffff, AX
+	JNE	diff64_avx2
+
+	ADDQ	$64, SI
+	ADDQ	$64, DI
+	SUBQ	$64, R8
+	CMPQ	R8, $64
+	JB	big_loop_avx2_exit
+	JMP	big_loop_avx2
+
+	// Avoid AVX->SSE transition penalty and search first 32 bytes of 64 byte chunk.
+diff32_avx2:
+	VZEROUPPER
+	JMP diff16
+
+	// Same as diff32_avx2, but for last 32 bytes.
+diff64_avx2:
+	VZEROUPPER
+	JMP diff48
+
+	// For <64 bytes remainder jump to normal loop.
+big_loop_avx2_exit:
+	VZEROUPPER
+	JMP loop
diff --git a/contrib/go/_std_1.20/src/internal/bytealg/compare_arm64.s b/contrib/go/_std_1.20/src/internal/bytealg/compare_arm64.s
new file mode 100644
index 0000000000..cc02c464e8
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/bytealg/compare_arm64.s
@@ -0,0 +1,125 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "go_asm.h"
+#include "textflag.h"
+
+TEXT ·Compare<ABIInternal>(SB),NOSPLIT|NOFRAME,$0-56
+	// R0 = a_base (want in R0)
+	// R1 = a_len  (want in R1)
+	// R2 = a_cap  (unused)
+	// R3 = b_base (want in R2)
+	// R4 = b_len  (want in R3)
+	// R5 = b_cap  (unused)
+	MOVD	R3, R2
+	MOVD	R4, R3
+	B	cmpbody<>(SB)
+
+TEXT runtime·cmpstring<ABIInternal>(SB),NOSPLIT|NOFRAME,$0-40
+	// R0 = a_base
+	// R1 = a_len
+	// R2 = b_base
+	// R3 = b_len
+	B	cmpbody<>(SB)
+
+// On entry:
+// R0 points to the start of a
+// R1 is the length of a
+// R2 points to the start of b
+// R3 is the length of b
+//
+// On exit:
+// R0 is the result
+// R4, R5, R6, R8, R9 and R10 are clobbered
+TEXT cmpbody<>(SB),NOSPLIT|NOFRAME,$0-0
+	CMP	R0, R2
+	BEQ	samebytes         // same starting pointers; compare lengths
+	CMP	R1, R3
+	CSEL	LT, R3, R1, R6    // R6 is min(R1, R3)
+
+	CBZ	R6, samebytes
+	BIC	$0xf, R6, R10
+	CBZ	R10, small        // length < 16
+	ADD	R0, R10           // end of chunk16
+	// length >= 16
+chunk16_loop:
+	LDP.P	16(R0), (R4, R8)
+	LDP.P	16(R2), (R5, R9)
+	CMP	R4, R5
+	BNE	cmp
+	CMP	R8, R9
+	BNE	cmpnext
+	CMP	R10, R0
+	BNE	chunk16_loop
+	AND	$0xf, R6, R6
+	CBZ	R6, samebytes
+	SUBS	$8, R6
+	BLT	tail
+	// the length of tail > 8 bytes
+	MOVD.P	8(R0), R4
+	MOVD.P	8(R2), R5
+	CMP	R4, R5
+	BNE	cmp
+	SUB	$8, R6
+	// compare last 8 bytes
+tail:
+	MOVD	(R0)(R6), R4
+	MOVD	(R2)(R6), R5
+	CMP	R4, R5
+	BEQ	samebytes
+cmp:
+	REV	R4, R4
+	REV	R5, R5
+	CMP	R4, R5
+ret:
+	MOVD	$1, R0
+	CNEG	HI, R0, R0
+	RET
+small:
+	TBZ	$3, R6, lt_8
+	MOVD	(R0), R4
+	MOVD	(R2), R5
+	CMP	R4, R5
+	BNE	cmp
+	SUBS	$8, R6
+	BEQ	samebytes
+	ADD	$8, R0
+	ADD	$8, R2
+	SUB	$8, R6
+	B	tail
+lt_8:
+	TBZ	$2, R6, lt_4
+	MOVWU	(R0), R4
+	MOVWU	(R2), R5
+	CMPW	R4, R5
+	BNE	cmp
+	SUBS	$4, R6
+	BEQ	samebytes
+	ADD	$4, R0
+	ADD	$4, R2
+lt_4:
+	TBZ	$1, R6, lt_2
+	MOVHU	(R0), R4
+	MOVHU	(R2), R5
+	CMPW	R4, R5
+	BNE	cmp
+	ADD	$2, R0
+	ADD	$2, R2
+lt_2:
+	TBZ	$0, R6, samebytes
+one:
+	MOVBU	(R0), R4
+	MOVBU	(R2), R5
+	CMPW	R4, R5
+	BNE	ret
+samebytes:
+	CMP	R3, R1
+	CSET	NE, R0
+	CNEG	LO, R0, R0
+	RET
+cmpnext:
+	REV	R8, R4
+	REV	R9, R5
+	CMP	R4, R5
+	B	ret
diff --git a/contrib/go/_std_1.20/src/internal/bytealg/compare_native.go b/contrib/go/_std_1.20/src/internal/bytealg/compare_native.go
new file mode 100644
index 0000000000..e016430075
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/bytealg/compare_native.go
@@ -0,0 +1,20 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build 386 || amd64 || s390x || arm || arm64 || loong64 || ppc64 || ppc64le || mips || mipsle || wasm || mips64 || mips64le || riscv64
+
+package bytealg
+
+import _ "unsafe"
+// For go:linkname
+
+//go:noescape
+func Compare(a, b []byte) int
+
+// The declaration below generates ABI wrappers for functions
+// implemented in assembly in this package but declared in another
+// package.
+
+//go:linkname abigen_runtime_cmpstring runtime.cmpstring
+func abigen_runtime_cmpstring(a, b string) int
diff --git a/contrib/go/_std_1.20/src/internal/bytealg/count_amd64.s b/contrib/go/_std_1.20/src/internal/bytealg/count_amd64.s
new file mode 100644
index 0000000000..efb17f84b7
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/bytealg/count_amd64.s
@@ -0,0 +1,208 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "go_asm.h"
+#include "asm_amd64.h"
+#include "textflag.h"
+
+TEXT ·Count(SB),NOSPLIT,$0-40
+#ifndef hasPOPCNT
+	CMPB	internal∕cpu·X86+const_offsetX86HasPOPCNT(SB), $1
+	JEQ	2(PC)
+	JMP	·countGeneric(SB)
+#endif
+	MOVQ	b_base+0(FP), SI
+	MOVQ	b_len+8(FP), BX
+	MOVB	c+24(FP), AL
+	LEAQ	ret+32(FP), R8
+	JMP	countbody<>(SB)
+
+TEXT ·CountString(SB),NOSPLIT,$0-32
+#ifndef hasPOPCNT
+	CMPB	internal∕cpu·X86+const_offsetX86HasPOPCNT(SB), $1
+	JEQ	2(PC)
+	JMP	·countGenericString(SB)
+#endif
+	MOVQ	s_base+0(FP), SI
+	MOVQ	s_len+8(FP), BX
+	MOVB	c+16(FP), AL
+	LEAQ	ret+24(FP), R8
+	JMP	countbody<>(SB)
+
+// input:
+//   SI: data
+//   BX: data len
+//   AL: byte sought
+//   R8: address to put result
+// This function requires the POPCNT instruction.
+TEXT countbody<>(SB),NOSPLIT,$0
+	// Shuffle X0 around so that each byte contains
+	// the character we're looking for.
+	MOVD AX, X0
+	PUNPCKLBW X0, X0
+	PUNPCKLBW X0, X0
+	PSHUFL $0, X0, X0
+
+	CMPQ BX, $16
+	JLT small
+
+	MOVQ $0, R12 // Accumulator
+
+	MOVQ SI, DI
+
+	CMPQ BX, $32
+	JA avx2
+sse:
+	LEAQ	-16(SI)(BX*1), AX	// AX = address of last 16 bytes
+	JMP	sseloopentry
+
+sseloop:
+	// Move the next 16-byte chunk of the data into X1.
+	MOVOU	(DI), X1
+	// Compare bytes in X0 to X1.
+	PCMPEQB	X0, X1
+	// Take the top bit of each byte in X1 and put the result in DX.
+	PMOVMSKB X1, DX
+	// Count number of matching bytes
+	POPCNTL DX, DX
+	// Accumulate into R12
+	ADDQ DX, R12
+	// Advance to next block.
+	ADDQ	$16, DI
+sseloopentry:
+	CMPQ	DI, AX
+	JBE	sseloop
+
+	// Get the number of bytes to consider in the last 16 bytes
+	ANDQ $15, BX
+	JZ end
+
+	// Create mask to ignore overlap between previous 16 byte block
+	// and the next.
+	MOVQ $16,CX
+	SUBQ BX, CX
+	MOVQ $0xFFFF, R10
+	SARQ CL, R10
+	SALQ CL, R10
+
+	// Process the last 16-byte chunk. This chunk may overlap with the
+	// chunks we've already searched so we need to mask part of it.
+	MOVOU	(AX), X1
+	PCMPEQB	X0, X1
+	PMOVMSKB X1, DX
+	// Apply mask
+	ANDQ R10, DX
+	POPCNTL DX, DX
+	ADDQ DX, R12
+end:
+	MOVQ R12, (R8)
+	RET
+
+// handle for lengths < 16
+small:
+	TESTQ	BX, BX
+	JEQ	endzero
+
+	// Check if we'll load across a page boundary.
+	LEAQ	16(SI), AX
+	TESTW	$0xff0, AX
+	JEQ	endofpage
+
+	// We must ignore high bytes as they aren't part of our slice.
+	// Create mask.
+	MOVB BX, CX
+	MOVQ $1, R10
+	SALQ CL, R10
+	SUBQ $1, R10
+
+	// Load data
+	MOVOU	(SI), X1
+	// Compare target byte with each byte in data.
+	PCMPEQB	X0, X1
+	// Move result bits to integer register.
+	PMOVMSKB X1, DX
+	// Apply mask
+	ANDQ R10, DX
+	POPCNTL DX, DX
+	// Directly return DX, we don't need to accumulate
+	// since we have <16 bytes.
+	MOVQ	DX, (R8)
+	RET
+endzero:
+	MOVQ $0, (R8)
+	RET
+
+endofpage:
+	// We must ignore low bytes as they aren't part of our slice.
+	MOVQ $16,CX
+	SUBQ BX, CX
+	MOVQ $0xFFFF, R10
+	SARQ CL, R10
+	SALQ CL, R10
+
+	// Load data into the high end of X1.
+	MOVOU	-16(SI)(BX*1), X1
+	// Compare target byte with each byte in data.
+	PCMPEQB	X0, X1
+	// Move result bits to integer register.
+	PMOVMSKB X1, DX
+	// Apply mask
+	ANDQ R10, DX
+	// Directly return DX, we don't need to accumulate
+	// since we have <16 bytes.
+	POPCNTL DX, DX
+	MOVQ	DX, (R8)
+	RET
+
+avx2:
+#ifndef hasAVX2
+	CMPB   internal∕cpu·X86+const_offsetX86HasAVX2(SB), $1
+	JNE sse
+#endif
+	MOVD AX, X0
+	LEAQ -32(SI)(BX*1), R11
+	VPBROADCASTB  X0, Y1
+avx2_loop:
+	VMOVDQU (DI), Y2
+	VPCMPEQB Y1, Y2, Y3
+	VPMOVMSKB Y3, DX
+	POPCNTL DX, DX
+	ADDQ DX, R12
+	ADDQ $32, DI
+	CMPQ DI, R11
+	JLE avx2_loop
+
+	// If last block is already processed,
+	// skip to the end.
+	CMPQ DI, R11
+	JEQ endavx
+
+	// Load address of the last 32 bytes.
+	// There is an overlap with the previous block.
+	MOVQ R11, DI
+	VMOVDQU (DI), Y2
+	VPCMPEQB Y1, Y2, Y3
+	VPMOVMSKB Y3, DX
+	// Exit AVX mode.
+	VZEROUPPER
+
+	// Create mask to ignore overlap between previous 32 byte block
+	// and the next.
+	ANDQ $31, BX
+	MOVQ $32,CX
+	SUBQ BX, CX
+	MOVQ $0xFFFFFFFF, R10
+	SARQ CL, R10
+	SALQ CL, R10
+	// Apply mask
+	ANDQ R10, DX
+	POPCNTL DX, DX
+	ADDQ DX, R12
+	MOVQ R12, (R8)
+	RET
+endavx:
+	// Exit AVX mode.
+	VZEROUPPER
+	MOVQ R12, (R8)
+	RET
diff --git a/contrib/go/_std_1.20/src/internal/bytealg/count_arm64.s b/contrib/go/_std_1.20/src/internal/bytealg/count_arm64.s
new file mode 100644
index 0000000000..8cd703d943
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/bytealg/count_arm64.s
@@ -0,0 +1,90 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "go_asm.h"
+#include "textflag.h"
+
+TEXT ·Count(SB),NOSPLIT,$0-40
+	MOVD	b_base+0(FP), R0
+	MOVD	b_len+8(FP), R2
+	MOVBU	c+24(FP), R1
+	MOVD	$ret+32(FP), R8
+	B	countbytebody<>(SB)
+
+TEXT ·CountString(SB),NOSPLIT,$0-32
+	MOVD	s_base+0(FP), R0
+	MOVD	s_len+8(FP), R2
+	MOVBU	c+16(FP), R1
+	MOVD	$ret+24(FP), R8
+	B	countbytebody<>(SB)
+
+// input:
+//   R0: data
+//   R2: data len
+//   R1: byte to find
+//   R8: address to put result
+TEXT countbytebody<>(SB),NOSPLIT,$0
+	// R11 = count of byte to search
+	MOVD	$0, R11
+	// short path to handle 0-byte case
+	CBZ	R2, done
+	CMP	$0x20, R2
+	// jump directly to tail if length < 32
+	BLO	tail
+	ANDS	$0x1f, R0, R9
+	BEQ	chunk
+	// Work with not 32-byte aligned head
+	BIC	$0x1f, R0, R3
+	ADD	$0x20, R3
+head_loop:
+	MOVBU.P	1(R0), R5
+	CMP	R5, R1
+	CINC	EQ, R11, R11
+	SUB	$1, R2, R2
+	CMP	R0, R3
+	BNE	head_loop
+	// Work with 32-byte aligned chunks
+chunk:
+	BIC	$0x1f, R2, R9
+	// The first chunk can also be the last
+	CBZ	R9, tail
+	// R3 = end of 32-byte chunks
+	ADD	R0, R9, R3
+	MOVD	$1, R5
+	VMOV	R5, V5.B16
+	// R2 = length of tail
+	SUB	R9, R2, R2
+	// Duplicate R1 (byte to search) to 16 1-byte elements of V0
+	VMOV	R1, V0.B16
+	// Clear the low 64-bit element of V7 and V8
+	VEOR	V7.B8, V7.B8, V7.B8
+	VEOR	V8.B8, V8.B8, V8.B8
+	// Count the target byte in 32-byte chunk
+chunk_loop:
+	VLD1.P	(R0), [V1.B16, V2.B16]
+	CMP	R0, R3
+	VCMEQ	V0.B16, V1.B16, V3.B16
+	VCMEQ	V0.B16, V2.B16, V4.B16
+	// Clear the higher 7 bits
+	VAND	V5.B16, V3.B16, V3.B16
+	VAND	V5.B16, V4.B16, V4.B16
+	// Count lanes match the requested byte
+	VADDP	V4.B16, V3.B16, V6.B16 // 32B->16B
+	VUADDLV	V6.B16, V7
+	// Accumulate the count in low 64-bit element of V8 when inside the loop
+	VADD	V7, V8
+	BNE	chunk_loop
+	VMOV	V8.D[0], R6
+	ADD	R6, R11, R11
+	CBZ	R2, done
+tail:
+	// Work with tail shorter than 32 bytes
+	MOVBU.P	1(R0), R5
+	SUB	$1, R2, R2
+	CMP	R5, R1
+	CINC	EQ, R11, R11
+	CBNZ	R2, tail
+done:
+	MOVD	R11, (R8)
+	RET
diff --git a/contrib/go/_std_1.20/src/internal/bytealg/count_native.go b/contrib/go/_std_1.20/src/internal/bytealg/count_native.go
new file mode 100644
index 0000000000..90189c9fe0
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/bytealg/count_native.go
@@ -0,0 +1,33 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build amd64 || arm || arm64 || ppc64le || ppc64 || riscv64 || s390x
+
+package bytealg
+
+//go:noescape
+func Count(b []byte, c byte) int
+
+//go:noescape
+func CountString(s string, c byte) int
+
+// A backup implementation to use by assembly.
+func countGeneric(b []byte, c byte) int {
+	n := 0
+	for _, x := range b {
+		if x == c {
+			n++
+		}
+	}
+	return n
+}
+func countGenericString(s string, c byte) int {
+	n := 0
+	for i := 0; i < len(s); i++ {
+		if s[i] == c {
+			n++
+		}
+	}
+	return n
+}
diff --git a/contrib/go/_std_1.20/src/internal/bytealg/equal_amd64.s b/contrib/go/_std_1.20/src/internal/bytealg/equal_amd64.s
new file mode 100644
index 0000000000..d178a33779
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/bytealg/equal_amd64.s
@@ -0,0 +1,162 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "go_asm.h"
+#include "asm_amd64.h"
+#include "textflag.h"
+
+// memequal(a, b unsafe.Pointer, size uintptr) bool
+TEXT runtime·memequal<ABIInternal>(SB),NOSPLIT,$0-25
+	// AX = a    (want in SI)
+	// BX = b    (want in DI)
+	// CX = size (want in BX)
+	CMPQ	AX, BX
+	JNE	neq
+	MOVQ	$1, AX	// return 1
+	RET
+neq:
+	MOVQ	AX, SI
+	MOVQ	BX, DI
+	MOVQ	CX, BX
+	JMP	memeqbody<>(SB)
+
+// memequal_varlen(a, b unsafe.Pointer) bool
+TEXT runtime·memequal_varlen<ABIInternal>(SB),NOSPLIT,$0-17
+	// AX = a       (want in SI)
+	// BX = b       (want in DI)
+	// 8(DX) = size (want in BX)
+	CMPQ	AX, BX
+	JNE	neq
+	MOVQ	$1, AX	// return 1
+	RET
+neq:
+	MOVQ	AX, SI
+	MOVQ	BX, DI
+	MOVQ	8(DX), BX    // compiler stores size at offset 8 in the closure
+	JMP	memeqbody<>(SB)
+
+// Input:
+//   a in SI
+//   b in DI
+//   count in BX
+// Output:
+//   result in AX
+TEXT memeqbody<>(SB),NOSPLIT,$0-0
+	CMPQ	BX, $8
+	JB	small
+	CMPQ	BX, $64
+	JB	bigloop
+#ifndef hasAVX2
+	CMPB	internal∕cpu·X86+const_offsetX86HasAVX2(SB), $1
+	JE	hugeloop_avx2
+
+	// 64 bytes at a time using xmm registers
+hugeloop:
+	CMPQ	BX, $64
+	JB	bigloop
+	MOVOU	(SI), X0
+	MOVOU	(DI), X1
+	MOVOU	16(SI), X2
+	MOVOU	16(DI), X3
+	MOVOU	32(SI), X4
+	MOVOU	32(DI), X5
+	MOVOU	48(SI), X6
+	MOVOU	48(DI), X7
+	PCMPEQB	X1, X0
+	PCMPEQB	X3, X2
+	PCMPEQB	X5, X4
+	PCMPEQB	X7, X6
+	PAND	X2, X0
+	PAND	X6, X4
+	PAND	X4, X0
+	PMOVMSKB X0, DX
+	ADDQ	$64, SI
+	ADDQ	$64, DI
+	SUBQ	$64, BX
+	CMPL	DX, $0xffff
+	JEQ	hugeloop
+	XORQ	AX, AX	// return 0
+	RET
+#endif
+
+	// 64 bytes at a time using ymm registers
+hugeloop_avx2:
+	CMPQ	BX, $64
+	JB	bigloop_avx2
+	VMOVDQU	(SI), Y0
+	VMOVDQU	(DI), Y1
+	VMOVDQU	32(SI), Y2
+	VMOVDQU	32(DI), Y3
+	VPCMPEQB	Y1, Y0, Y4
+	VPCMPEQB	Y2, Y3, Y5
+	VPAND	Y4, Y5, Y6
+	VPMOVMSKB Y6, DX
+	ADDQ	$64, SI
+	ADDQ	$64, DI
+	SUBQ	$64, BX
+	CMPL	DX, $0xffffffff
+	JEQ	hugeloop_avx2
+	VZEROUPPER
+	XORQ	AX, AX	// return 0
+	RET
+
+bigloop_avx2:
+	VZEROUPPER
+
+	// 8 bytes at a time using 64-bit register
+bigloop:
+	CMPQ	BX, $8
+	JBE	leftover
+	MOVQ	(SI), CX
+	MOVQ	(DI), DX
+	ADDQ	$8, SI
+	ADDQ	$8, DI
+	SUBQ	$8, BX
+	CMPQ	CX, DX
+	JEQ	bigloop
+	XORQ	AX, AX	// return 0
+	RET
+
+	// remaining 0-8 bytes
+leftover:
+	MOVQ	-8(SI)(BX*1), CX
+	MOVQ	-8(DI)(BX*1), DX
+	CMPQ	CX, DX
+	SETEQ	AX
+	RET
+
+small:
+	CMPQ	BX, $0
+	JEQ	equal
+
+	LEAQ	0(BX*8), CX
+	NEGQ	CX
+
+	CMPB	SI, $0xf8
+	JA	si_high
+
+	// load at SI won't cross a page boundary.
+	MOVQ	(SI), SI
+	JMP	si_finish
+si_high:
+	// address ends in 11111xxx. Load up to bytes we want, move to correct position.
+	MOVQ	-8(SI)(BX*1), SI
+	SHRQ	CX, SI
+si_finish:
+
+	// same for DI.
+	CMPB	DI, $0xf8
+	JA	di_high
+	MOVQ	(DI), DI
+	JMP	di_finish
+di_high:
+	MOVQ	-8(DI)(BX*1), DI
+	SHRQ	CX, DI
+di_finish:
+
+	SUBQ	SI, DI
+	SHLQ	CX, DI
+equal:
+	SETEQ	AX
+	RET
diff --git a/contrib/go/_std_1.20/src/internal/bytealg/equal_arm64.s b/contrib/go/_std_1.20/src/internal/bytealg/equal_arm64.s
new file mode 100644
index 0000000000..d3aabba587
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/bytealg/equal_arm64.s
@@ -0,0 +1,121 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "go_asm.h"
+#include "textflag.h"
+
+// memequal(a, b unsafe.Pointer, size uintptr) bool
+TEXT runtime·memequal<ABIInternal>(SB),NOSPLIT|NOFRAME,$0-25
+	// short path to handle 0-byte case
+	CBZ	R2, equal
+	B	memeqbody<>(SB)
+equal:
+	MOVD	$1, R0
+	RET
+
+// memequal_varlen(a, b unsafe.Pointer) bool
+TEXT runtime·memequal_varlen<ABIInternal>(SB),NOSPLIT,$0-17
+	CMP	R0, R1
+	BEQ	eq
+	MOVD	8(R26), R2    // compiler stores size at offset 8 in the closure
+	CBZ	R2, eq
+	B	memeqbody<>(SB)
+eq:
+	MOVD	$1, R0
+	RET
+
+// input:
+// R0: pointer a
+// R1: pointer b
+// R2: data len
+// at return: result in R0
+TEXT memeqbody<>(SB),NOSPLIT,$0
+	CMP	$1, R2
+	// handle 1-byte special case for better performance
+	BEQ	one
+	CMP	$16, R2
+	// handle specially if length < 16
+	BLO	tail
+	BIC	$0x3f, R2, R3
+	CBZ	R3, chunk16
+	// work with 64-byte chunks
+	ADD	R3, R0, R6	// end of chunks
+chunk64_loop:
+	VLD1.P	(R0), [V0.D2, V1.D2, V2.D2, V3.D2]
+	VLD1.P	(R1), [V4.D2, V5.D2, V6.D2, V7.D2]
+	VCMEQ	V0.D2, V4.D2, V8.D2
+	VCMEQ	V1.D2, V5.D2, V9.D2
+	VCMEQ	V2.D2, V6.D2, V10.D2
+	VCMEQ	V3.D2, V7.D2, V11.D2
+	VAND	V8.B16, V9.B16, V8.B16
+	VAND	V8.B16, V10.B16, V8.B16
+	VAND	V8.B16, V11.B16, V8.B16
+	CMP	R0, R6
+	VMOV	V8.D[0], R4
+	VMOV	V8.D[1], R5
+	CBZ	R4, not_equal
+	CBZ	R5, not_equal
+	BNE	chunk64_loop
+	AND	$0x3f, R2, R2
+	CBZ	R2, equal
+chunk16:
+	// work with 16-byte chunks
+	BIC	$0xf, R2, R3
+	CBZ	R3, tail
+	ADD	R3, R0, R6	// end of chunks
+chunk16_loop:
+	LDP.P	16(R0), (R4, R5)
+	LDP.P	16(R1), (R7, R9)
+	EOR	R4, R7
+	CBNZ	R7, not_equal
+	EOR	R5, R9
+	CBNZ	R9, not_equal
+	CMP	R0, R6
+	BNE	chunk16_loop
+	AND	$0xf, R2, R2
+	CBZ	R2, equal
+tail:
+	// special compare of tail with length < 16
+	TBZ	$3, R2, lt_8
+	MOVD	(R0), R4
+	MOVD	(R1), R5
+	EOR	R4, R5
+	CBNZ	R5, not_equal
+	SUB	$8, R2, R6	// offset of the last 8 bytes
+	MOVD	(R0)(R6), R4
+	MOVD	(R1)(R6), R5
+	EOR	R4, R5
+	CBNZ	R5, not_equal
+	B	equal
+lt_8:
+	TBZ	$2, R2, lt_4
+	MOVWU	(R0), R4
+	MOVWU	(R1), R5
+	EOR	R4, R5
+	CBNZ	R5, not_equal
+	SUB	$4, R2, R6	// offset of the last 4 bytes
+	MOVWU	(R0)(R6), R4
+	MOVWU	(R1)(R6), R5
+	EOR	R4, R5
+	CBNZ	R5, not_equal
+	B	equal
+lt_4:
+	TBZ	$1, R2, lt_2
+	MOVHU.P	2(R0), R4
+	MOVHU.P	2(R1), R5
+	CMP	R4, R5
+	BNE	not_equal
+lt_2:
+	TBZ	$0, R2, equal
+one:
+	MOVBU	(R0), R4
+	MOVBU	(R1), R5
+	CMP	R4, R5
+	BNE	not_equal
+equal:
+	MOVD	$1, R0
+	RET
+not_equal:
+	MOVB	ZR, R0
+	RET
diff --git a/contrib/go/_std_1.20/src/internal/bytealg/equal_generic.go b/contrib/go/_std_1.20/src/internal/bytealg/equal_generic.go
new file mode 100644
index 0000000000..59bdf8fdd5
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/bytealg/equal_generic.go
@@ -0,0 +1,18 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package bytealg
+
+// Equal reports whether a and b
+// are the same length and contain the same bytes.
+// A nil argument is equivalent to an empty slice.
+//
+// Equal is equivalent to bytes.Equal.
+// It is provided here for convenience,
+// because some packages cannot depend on bytes.
+func Equal(a, b []byte) bool {
+	// Neither cmd/compile nor gccgo allocates for these string conversions.
+	// There is a test for this in package bytes.
+	return string(a) == string(b)
+}
diff --git a/contrib/go/_std_1.20/src/internal/bytealg/equal_native.go b/contrib/go/_std_1.20/src/internal/bytealg/equal_native.go
new file mode 100644
index 0000000000..cf3a245bc0
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/bytealg/equal_native.go
@@ -0,0 +1,21 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package bytealg
+
+import "unsafe"
+
+// The declarations below generate ABI wrappers for functions
+// implemented in assembly in this package but declared in another
+// package.
+
+// The compiler generates calls to runtime.memequal and runtime.memequal_varlen.
+// In addition, the runtime calls runtime.memequal explicitly.
+// Those functions are implemented in this package.
+
+//go:linkname abigen_runtime_memequal runtime.memequal
+func abigen_runtime_memequal(a, b unsafe.Pointer, size uintptr) bool
+
+//go:linkname abigen_runtime_memequal_varlen runtime.memequal_varlen
+func abigen_runtime_memequal_varlen(a, b unsafe.Pointer) bool
diff --git a/contrib/go/_std_1.20/src/internal/bytealg/index_amd64.go b/contrib/go/_std_1.20/src/internal/bytealg/index_amd64.go
new file mode 100644
index 0000000000..c7a1941e5f
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/bytealg/index_amd64.go
@@ -0,0 +1,26 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package bytealg
+
+import "internal/cpu"
+
+const MaxBruteForce = 64
+
+func init() {
+	if cpu.X86.HasAVX2 {
+		MaxLen = 63
+	} else {
+		MaxLen = 31
+	}
+}
+
+// Cutover reports the number of failures of IndexByte we should tolerate
+// before switching over to Index.
+// n is the number of bytes processed so far.
+// See the bytes.Index implementation for details.
+func Cutover(n int) int {
+	// 1 error per 8 characters, plus a few slop to start.
+	return (n + 16) / 8
+}
diff --git a/contrib/go/_std_1.20/src/internal/bytealg/index_amd64.s b/contrib/go/_std_1.20/src/internal/bytealg/index_amd64.s
new file mode 100644
index 0000000000..04314917b8
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/bytealg/index_amd64.s
@@ -0,0 +1,276 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "go_asm.h"
+#include "textflag.h"
+
+TEXT ·Index(SB),NOSPLIT,$0-56
+	MOVQ a_base+0(FP), DI
+	MOVQ a_len+8(FP), DX
+	MOVQ b_base+24(FP), R8
+	MOVQ b_len+32(FP), AX
+	MOVQ DI, R10
+	LEAQ ret+48(FP), R11
+	JMP  indexbody<>(SB)
+
+TEXT ·IndexString(SB),NOSPLIT,$0-40
+	MOVQ a_base+0(FP), DI
+	MOVQ a_len+8(FP), DX
+	MOVQ b_base+16(FP), R8
+	MOVQ b_len+24(FP), AX
+	MOVQ DI, R10
+	LEAQ ret+32(FP), R11
+	JMP  indexbody<>(SB)
+
+// AX: length of string, that we are searching for
+// DX: length of string, in which we are searching
+// DI: pointer to string, in which we are searching
+// R8: pointer to string, that we are searching for
+// R11: address, where to put return value
+// Note: We want len in DX and AX, because PCMPESTRI implicitly consumes them
+TEXT indexbody<>(SB),NOSPLIT,$0
+	CMPQ AX, DX
+	JA fail
+	CMPQ DX, $16
+	JAE sse42
+no_sse42:
+	CMPQ AX, $2
+	JA   _3_or_more
+	MOVW (R8), R8
+	LEAQ -1(DI)(DX*1), DX
+loop2:
+	MOVW (DI), SI
+	CMPW SI,R8
+	JZ success
+	ADDQ $1,DI
+	CMPQ DI,DX
+	JB loop2
+	JMP fail
+_3_or_more:
+	CMPQ AX, $3
+	JA   _4_or_more
+	MOVW 1(R8), BX
+	MOVW (R8), R8
+	LEAQ -2(DI)(DX*1), DX
+loop3:
+	MOVW (DI), SI
+	CMPW SI,R8
+	JZ   partial_success3
+	ADDQ $1,DI
+	CMPQ DI,DX
+	JB loop3
+	JMP fail
+partial_success3:
+	MOVW 1(DI), SI
+	CMPW SI,BX
+	JZ success
+	ADDQ $1,DI
+	CMPQ DI,DX
+	JB loop3
+	JMP fail
+_4_or_more:
+	CMPQ AX, $4
+	JA   _5_or_more
+	MOVL (R8), R8
+	LEAQ -3(DI)(DX*1), DX
+loop4:
+	MOVL (DI), SI
+	CMPL SI,R8
+	JZ   success
+	ADDQ $1,DI
+	CMPQ DI,DX
+	JB loop4
+	JMP fail
+_5_or_more:
+	CMPQ AX, $7
+	JA   _8_or_more
+	LEAQ 1(DI)(DX*1), DX
+	SUBQ AX, DX
+	MOVL -4(R8)(AX*1), BX
+	MOVL (R8), R8
+loop5to7:
+	MOVL (DI), SI
+	CMPL SI,R8
+	JZ   partial_success5to7
+	ADDQ $1,DI
+	CMPQ DI,DX
+	JB loop5to7
+	JMP fail
+partial_success5to7:
+	MOVL -4(AX)(DI*1), SI
+	CMPL SI,BX
+	JZ success
+	ADDQ $1,DI
+	CMPQ DI,DX
+	JB loop5to7
+	JMP fail
+_8_or_more:
+	CMPQ AX, $8
+	JA   _9_or_more
+	MOVQ (R8), R8
+	LEAQ -7(DI)(DX*1), DX
+loop8:
+	MOVQ (DI), SI
+	CMPQ SI,R8
+	JZ   success
+	ADDQ $1,DI
+	CMPQ DI,DX
+	JB loop8
+	JMP fail
+_9_or_more:
+	CMPQ AX, $15
+	JA   _16_or_more
+	LEAQ 1(DI)(DX*1), DX
+	SUBQ AX, DX
+	MOVQ -8(R8)(AX*1), BX
+	MOVQ (R8), R8
+loop9to15:
+	MOVQ (DI), SI
+	CMPQ SI,R8
+	JZ   partial_success9to15
+	ADDQ $1,DI
+	CMPQ DI,DX
+	JB loop9to15
+	JMP fail
+partial_success9to15:
+	MOVQ -8(AX)(DI*1), SI
+	CMPQ SI,BX
+	JZ success
+	ADDQ $1,DI
+	CMPQ DI,DX
+	JB loop9to15
+	JMP fail
+_16_or_more:
+	CMPQ AX, $16
+	JA   _17_or_more
+	MOVOU (R8), X1
+	LEAQ -15(DI)(DX*1), DX
+loop16:
+	MOVOU (DI), X2
+	PCMPEQB X1, X2
+	PMOVMSKB X2, SI
+	CMPQ  SI, $0xffff
+	JE   success
+	ADDQ $1,DI
+	CMPQ DI,DX
+	JB loop16
+	JMP fail
+_17_or_more:
+	CMPQ AX, $31
+	JA   _32_or_more
+	LEAQ 1(DI)(DX*1), DX
+	SUBQ AX, DX
+	MOVOU -16(R8)(AX*1), X0
+	MOVOU (R8), X1
+loop17to31:
+	MOVOU (DI), X2
+	PCMPEQB X1,X2
+	PMOVMSKB X2, SI
+	CMPQ  SI, $0xffff
+	JE   partial_success17to31
+	ADDQ $1,DI
+	CMPQ DI,DX
+	JB loop17to31
+	JMP fail
+partial_success17to31:
+	MOVOU -16(AX)(DI*1), X3
+	PCMPEQB X0, X3
+	PMOVMSKB X3, SI
+	CMPQ  SI, $0xffff
+	JE success
+	ADDQ $1,DI
+	CMPQ DI,DX
+	JB loop17to31
+	JMP fail
+// We can get here only when AVX2 is enabled and cutoff for indexShortStr is set to 63
+// So no need to check cpuid
+_32_or_more:
+	CMPQ AX, $32
+	JA   _33_to_63
+	VMOVDQU (R8), Y1
+	LEAQ -31(DI)(DX*1), DX
+loop32:
+	VMOVDQU (DI), Y2
+	VPCMPEQB Y1, Y2, Y3
+	VPMOVMSKB Y3, SI
+	CMPL  SI, $0xffffffff
+	JE   success_avx2
+	ADDQ $1,DI
+	CMPQ DI,DX
+	JB loop32
+	JMP fail_avx2
+_33_to_63:
+	LEAQ 1(DI)(DX*1), DX
+	SUBQ AX, DX
+	VMOVDQU -32(R8)(AX*1), Y0
+	VMOVDQU (R8), Y1
+loop33to63:
+	VMOVDQU (DI), Y2
+	VPCMPEQB Y1, Y2, Y3
+	VPMOVMSKB Y3, SI
+	CMPL  SI, $0xffffffff
+	JE   partial_success33to63
+	ADDQ $1,DI
+	CMPQ DI,DX
+	JB loop33to63
+	JMP fail_avx2
+partial_success33to63:
+	VMOVDQU -32(AX)(DI*1), Y3
+	VPCMPEQB Y0, Y3, Y4
+	VPMOVMSKB Y4, SI
+	CMPL  SI, $0xffffffff
+	JE success_avx2
+	ADDQ $1,DI
+	CMPQ DI,DX
+	JB loop33to63
+fail_avx2:
+	VZEROUPPER
+fail:
+	MOVQ $-1, (R11)
+	RET
+success_avx2:
+	VZEROUPPER
+	JMP success
+sse42:
+#ifndef hasSSE42
+	CMPB internal∕cpu·X86+const_offsetX86HasSSE42(SB), $1
+	JNE no_sse42
+#endif
+	CMPQ AX, $12
+	// PCMPESTRI is slower than normal compare,
+	// so using it makes sense only if we advance 4+ bytes per compare
+	// This value was determined experimentally and is the ~same
+	// on Nehalem (first with SSE42) and Haswell.
+	JAE _9_or_more
+	LEAQ 16(R8), SI
+	TESTW $0xff0, SI
+	JEQ no_sse42
+	MOVOU (R8), X1
+	LEAQ -15(DI)(DX*1), SI
+	MOVQ $16, R9
+	SUBQ AX, R9 // We advance by 16-len(sep) each iteration, so precalculate it into R9
+loop_sse42:
+	// 0x0c means: unsigned byte compare (bits 0,1 are 00)
+	// for equality (bits 2,3 are 11)
+	// result is not masked or inverted (bits 4,5 are 00)
+	// and corresponds to first matching byte (bit 6 is 0)
+	PCMPESTRI $0x0c, (DI), X1
+	// CX == 16 means no match,
+	// CX > R9 means partial match at the end of the string,
+	// otherwise sep is at offset CX from X1 start
+	CMPQ CX, R9
+	JBE sse42_success
+	ADDQ R9, DI
+	CMPQ DI, SI
+	JB loop_sse42
+	PCMPESTRI $0x0c, -1(SI), X1
+	CMPQ CX, R9
+	JA fail
+	LEAQ -1(SI), DI
+sse42_success:
+	ADDQ CX, DI
+success:
+	SUBQ R10, DI
+	MOVQ DI, (R11)
+	RET
diff --git a/contrib/go/_std_1.20/src/internal/bytealg/index_arm64.go b/contrib/go/_std_1.20/src/internal/bytealg/index_arm64.go
new file mode 100644
index 0000000000..e87c109519
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/bytealg/index_arm64.go
@@ -0,0 +1,23 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package bytealg
+
+// Empirical data shows that using Index can get better
+// performance when len(s) <= 16.
+const MaxBruteForce = 16
+
+func init() {
+	// Optimize cases where the length of the substring is less than 32 bytes
+	MaxLen = 32
+}
+
+// Cutover reports the number of failures of IndexByte we should tolerate
+// before switching over to Index.
+// n is the number of bytes processed so far.
+// See the bytes.Index implementation for details.
+func Cutover(n int) int {
+	// 1 error per 16 characters, plus a few slop to start.
+	return 4 + n>>4
+}
diff --git a/contrib/go/_std_1.20/src/internal/bytealg/index_arm64.s b/contrib/go/_std_1.20/src/internal/bytealg/index_arm64.s
new file mode 100644
index 0000000000..3a551a72da
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/bytealg/index_arm64.s
@@ -0,0 +1,206 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "go_asm.h"
+#include "textflag.h"
+
+TEXT ·Index(SB),NOSPLIT,$0-56
+	MOVD	a_base+0(FP), R0
+	MOVD	a_len+8(FP), R1
+	MOVD	b_base+24(FP), R2
+	MOVD	b_len+32(FP), R3
+	MOVD	$ret+48(FP), R9
+	B	indexbody<>(SB)
+
+TEXT ·IndexString(SB),NOSPLIT,$0-40
+	MOVD	a_base+0(FP), R0
+	MOVD	a_len+8(FP), R1
+	MOVD	b_base+16(FP), R2
+	MOVD	b_len+24(FP), R3
+	MOVD	$ret+32(FP), R9
+	B	indexbody<>(SB)
+
+// input:
+//   R0: haystack
+//   R1: length of haystack
+//   R2: needle
+//   R3: length of needle (2 <= len <= 32)
+//   R9: address to put result
+TEXT indexbody<>(SB),NOSPLIT,$0-56
+	// main idea is to load 'sep' into separate register(s)
+	// to avoid repeatedly re-load it again and again
+	// for sebsequent substring comparisons
+	SUB	R3, R1, R4
+	// R4 contains the start of last substring for comparison
+	ADD	R0, R4, R4
+	ADD	$1, R0, R8
+
+	CMP	$8, R3
+	BHI	greater_8
+	TBZ	$3, R3, len_2_7
+len_8:
+	// R5 contains 8-byte of sep
+	MOVD	(R2), R5
+loop_8:
+	// R6 contains substring for comparison
+	CMP	R4, R0
+	BHI	not_found
+	MOVD.P	1(R0), R6
+	CMP	R5, R6
+	BNE	loop_8
+	B	found
+len_2_7:
+	TBZ	$2, R3, len_2_3
+	TBZ	$1, R3, len_4_5
+	TBZ	$0, R3, len_6
+len_7:
+	// R5 and R6 contain 7-byte of sep
+	MOVWU	(R2), R5
+	// 1-byte overlap with R5
+	MOVWU	3(R2), R6
+loop_7:
+	CMP	R4, R0
+	BHI	not_found
+	MOVWU.P	1(R0), R3
+	CMP	R5, R3
+	BNE	loop_7
+	MOVWU	2(R0), R3
+	CMP	R6, R3
+	BNE	loop_7
+	B	found
+len_6:
+	// R5 and R6 contain 6-byte of sep
+	MOVWU	(R2), R5
+	MOVHU	4(R2), R6
+loop_6:
+	CMP	R4, R0
+	BHI	not_found
+	MOVWU.P	1(R0), R3
+	CMP	R5, R3
+	BNE	loop_6
+	MOVHU	3(R0), R3
+	CMP	R6, R3
+	BNE	loop_6
+	B	found
+len_4_5:
+	TBZ	$0, R3, len_4
+len_5:
+	// R5 and R7 contain 5-byte of sep
+	MOVWU	(R2), R5
+	MOVBU	4(R2), R7
+loop_5:
+	CMP	R4, R0
+	BHI	not_found
+	MOVWU.P	1(R0), R3
+	CMP	R5, R3
+	BNE	loop_5
+	MOVBU	3(R0), R3
+	CMP	R7, R3
+	BNE	loop_5
+	B	found
+len_4:
+	// R5 contains 4-byte of sep
+	MOVWU	(R2), R5
+loop_4:
+	CMP	R4, R0
+	BHI	not_found
+	MOVWU.P	1(R0), R6
+	CMP	R5, R6
+	BNE	loop_4
+	B	found
+len_2_3:
+	TBZ	$0, R3, len_2
+len_3:
+	// R6 and R7 contain 3-byte of sep
+	MOVHU	(R2), R6
+	MOVBU	2(R2), R7
+loop_3:
+	CMP	R4, R0
+	BHI	not_found
+	MOVHU.P	1(R0), R3
+	CMP	R6, R3
+	BNE	loop_3
+	MOVBU	1(R0), R3
+	CMP	R7, R3
+	BNE	loop_3
+	B	found
+len_2:
+	// R5 contains 2-byte of sep
+	MOVHU	(R2), R5
+loop_2:
+	CMP	R4, R0
+	BHI	not_found
+	MOVHU.P	1(R0), R6
+	CMP	R5, R6
+	BNE	loop_2
+found:
+	SUB	R8, R0, R0
+	MOVD	R0, (R9)
+	RET
+not_found:
+	MOVD	$-1, R0
+	MOVD	R0, (R9)
+	RET
+greater_8:
+	SUB	$9, R3, R11	// len(sep) - 9, offset of R0 for last 8 bytes
+	CMP	$16, R3
+	BHI	greater_16
+len_9_16:
+	MOVD.P	8(R2), R5	// R5 contains the first 8-byte of sep
+	SUB	$16, R3, R7	// len(sep) - 16, offset of R2 for last 8 bytes
+	MOVD	(R2)(R7), R6	// R6 contains the last 8-byte of sep
+loop_9_16:
+	// search the first 8 bytes first
+	CMP	R4, R0
+	BHI	not_found
+	MOVD.P	1(R0), R7
+	CMP	R5, R7
+	BNE	loop_9_16
+	MOVD	(R0)(R11), R7
+	CMP	R6, R7		// compare the last 8 bytes
+	BNE	loop_9_16
+	B	found
+greater_16:
+	CMP	$24, R3
+	BHI	len_25_32
+len_17_24:
+	LDP.P	16(R2), (R5, R6)	// R5 and R6 contain the first 16-byte of sep
+	SUB	$24, R3, R10		// len(sep) - 24
+	MOVD	(R2)(R10), R7		// R7 contains the last 8-byte of sep
+loop_17_24:
+	// search the first 16 bytes first
+	CMP	R4, R0
+	BHI	not_found
+	MOVD.P	1(R0), R10
+	CMP	R5, R10
+	BNE	loop_17_24
+	MOVD	7(R0), R10
+	CMP	R6, R10
+	BNE	loop_17_24
+	MOVD	(R0)(R11), R10
+	CMP	R7, R10		// compare the last 8 bytes
+	BNE	loop_17_24
+	B	found
+len_25_32:
+	LDP.P	16(R2), (R5, R6)
+	MOVD.P	8(R2), R7	// R5, R6 and R7 contain the first 24-byte of sep
+	SUB	$32, R3, R12	// len(sep) - 32
+	MOVD	(R2)(R12), R10	// R10 contains the last 8-byte of sep
+loop_25_32:
+	// search the first 24 bytes first
+	CMP	R4, R0
+	BHI	not_found
+	MOVD.P	1(R0), R12
+	CMP	R5, R12
+	BNE	loop_25_32
+	MOVD	7(R0), R12
+	CMP	R6, R12
+	BNE	loop_25_32
+	MOVD	15(R0), R12
+	CMP	R7, R12
+	BNE	loop_25_32
+	MOVD	(R0)(R11), R12
+	CMP	R10, R12	// compare the last 8 bytes
+	BNE	loop_25_32
+	B	found
diff --git a/contrib/go/_std_1.20/src/internal/bytealg/index_native.go b/contrib/go/_std_1.20/src/internal/bytealg/index_native.go
new file mode 100644
index 0000000000..6e4a2f39e4
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/bytealg/index_native.go
@@ -0,0 +1,19 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build amd64 || arm64 || s390x || ppc64le || ppc64
+
+package bytealg
+
+//go:noescape
+
+// Index returns the index of the first instance of b in a, or -1 if b is not present in a.
+// Requires 2 <= len(b) <= MaxLen.
+func Index(a, b []byte) int
+
+//go:noescape
+
+// IndexString returns the index of the first instance of b in a, or -1 if b is not present in a.
+// Requires 2 <= len(b) <= MaxLen.
+func IndexString(a, b string) int
diff --git a/contrib/go/_std_1.20/src/internal/bytealg/indexbyte_amd64.s b/contrib/go/_std_1.20/src/internal/bytealg/indexbyte_amd64.s
new file mode 100644
index 0000000000..1ca70e39e2
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/bytealg/indexbyte_amd64.s
@@ -0,0 +1,149 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "go_asm.h"
+#include "textflag.h"
+
+TEXT	·IndexByte(SB), NOSPLIT, $0-40
+	MOVQ b_base+0(FP), SI
+	MOVQ b_len+8(FP), BX
+	MOVB c+24(FP), AL
+	LEAQ ret+32(FP), R8
+	JMP  indexbytebody<>(SB)
+
+TEXT	·IndexByteString(SB), NOSPLIT, $0-32
+	MOVQ s_base+0(FP), SI
+	MOVQ s_len+8(FP), BX
+	MOVB c+16(FP), AL
+	LEAQ ret+24(FP), R8
+	JMP  indexbytebody<>(SB)
+
+// input:
+//   SI: data
+//   BX: data len
+//   AL: byte sought
+//   R8: address to put result
+TEXT	indexbytebody<>(SB), NOSPLIT, $0
+	// Shuffle X0 around so that each byte contains
+	// the character we're looking for.
+	MOVD AX, X0
+	PUNPCKLBW X0, X0
+	PUNPCKLBW X0, X0
+	PSHUFL $0, X0, X0
+
+	CMPQ BX, $16
+	JLT small
+
+	MOVQ SI, DI
+
+	CMPQ BX, $32
+	JA avx2
+sse:
+	LEAQ	-16(SI)(BX*1), AX	// AX = address of last 16 bytes
+	JMP	sseloopentry
+
+sseloop:
+	// Move the next 16-byte chunk of the data into X1.
+	MOVOU	(DI), X1
+	// Compare bytes in X0 to X1.
+	PCMPEQB	X0, X1
+	// Take the top bit of each byte in X1 and put the result in DX.
+	PMOVMSKB X1, DX
+	// Find first set bit, if any.
+	BSFL	DX, DX
+	JNZ	ssesuccess
+	// Advance to next block.
+	ADDQ	$16, DI
+sseloopentry:
+	CMPQ	DI, AX
+	JB	sseloop
+
+	// Search the last 16-byte chunk. This chunk may overlap with the
+	// chunks we've already searched, but that's ok.
+	MOVQ	AX, DI
+	MOVOU	(AX), X1
+	PCMPEQB	X0, X1
+	PMOVMSKB X1, DX
+	BSFL	DX, DX
+	JNZ	ssesuccess
+
+failure:
+	MOVQ $-1, (R8)
+	RET
+
+// We've found a chunk containing the byte.
+// The chunk was loaded from DI.
+// The index of the matching byte in the chunk is DX.
+// The start of the data is SI.
+ssesuccess:
+	SUBQ SI, DI	// Compute offset of chunk within data.
+	ADDQ DX, DI	// Add offset of byte within chunk.
+	MOVQ DI, (R8)
+	RET
+
+// handle for lengths < 16
+small:
+	TESTQ	BX, BX
+	JEQ	failure
+
+	// Check if we'll load across a page boundary.
+	LEAQ	16(SI), AX
+	TESTW	$0xff0, AX
+	JEQ	endofpage
+
+	MOVOU	(SI), X1 // Load data
+	PCMPEQB	X0, X1	// Compare target byte with each byte in data.
+	PMOVMSKB X1, DX	// Move result bits to integer register.
+	BSFL	DX, DX	// Find first set bit.
+	JZ	failure	// No set bit, failure.
+	CMPL	DX, BX
+	JAE	failure	// Match is past end of data.
+	MOVQ	DX, (R8)
+	RET
+
+endofpage:
+	MOVOU	-16(SI)(BX*1), X1	// Load data into the high end of X1.
+	PCMPEQB	X0, X1	// Compare target byte with each byte in data.
+	PMOVMSKB X1, DX	// Move result bits to integer register.
+	MOVL	BX, CX
+	SHLL	CX, DX
+	SHRL	$16, DX	// Shift desired bits down to bottom of register.
+	BSFL	DX, DX	// Find first set bit.
+	JZ	failure	// No set bit, failure.
+	MOVQ	DX, (R8)
+	RET
+
+avx2:
+#ifndef hasAVX2
+	CMPB   internal∕cpu·X86+const_offsetX86HasAVX2(SB), $1
+	JNE sse
+#endif
+	MOVD AX, X0
+	LEAQ -32(SI)(BX*1), R11
+	VPBROADCASTB  X0, Y1
+avx2_loop:
+	VMOVDQU (DI), Y2
+	VPCMPEQB Y1, Y2, Y3
+	VPTEST Y3, Y3
+	JNZ avx2success
+	ADDQ $32, DI
+	CMPQ DI, R11
+	JLT avx2_loop
+	MOVQ R11, DI
+	VMOVDQU (DI), Y2
+	VPCMPEQB Y1, Y2, Y3
+	VPTEST Y3, Y3
+	JNZ avx2success
+	VZEROUPPER
+	MOVQ $-1, (R8)
+	RET
+
+avx2success:
+	VPMOVMSKB Y3, DX
+	BSFL DX, DX
+	SUBQ SI, DI
+	ADDQ DI, DX
+	MOVQ DX, (R8)
+	VZEROUPPER
+	RET
diff --git a/contrib/go/_std_1.20/src/internal/bytealg/indexbyte_arm64.s b/contrib/go/_std_1.20/src/internal/bytealg/indexbyte_arm64.s
new file mode 100644
index 0000000000..40843fbc5b
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/bytealg/indexbyte_arm64.s
@@ -0,0 +1,126 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "textflag.h"
+
+TEXT ·IndexByte(SB),NOSPLIT,$0-40
+	MOVD	b_base+0(FP), R0
+	MOVD	b_len+8(FP), R2
+	MOVBU	c+24(FP), R1
+	MOVD	$ret+32(FP), R8
+	B	indexbytebody<>(SB)
+
+TEXT ·IndexByteString(SB),NOSPLIT,$0-32
+	MOVD	s_base+0(FP), R0
+	MOVD	s_len+8(FP), R2
+	MOVBU	c+16(FP), R1
+	MOVD	$ret+24(FP), R8
+	B	indexbytebody<>(SB)
+
+// input:
+//   R0: data
+//   R1: byte to search
+//   R2: data len
+//   R8: address to put result
+TEXT indexbytebody<>(SB),NOSPLIT,$0
+	// Core algorithm:
+	// For each 32-byte chunk we calculate a 64-bit syndrome value,
+	// with two bits per byte. For each tuple, bit 0 is set if the
+	// relevant byte matched the requested character and bit 1 is
+	// not used (faster than using a 32bit syndrome). Since the bits
+	// in the syndrome reflect exactly the order in which things occur
+	// in the original string, counting trailing zeros allows to
+	// identify exactly which byte has matched.
+
+	CBZ	R2, fail
+	MOVD	R0, R11
+	// Magic constant 0x40100401 allows us to identify
+	// which lane matches the requested byte.
+	// 0x40100401 = ((1<<0) + (4<<8) + (16<<16) + (64<<24))
+	// Different bytes have different bit masks (i.e: 1, 4, 16, 64)
+	MOVD	$0x40100401, R5
+	VMOV	R1, V0.B16
+	// Work with aligned 32-byte chunks
+	BIC	$0x1f, R0, R3
+	VMOV	R5, V5.S4
+	ANDS	$0x1f, R0, R9
+	AND	$0x1f, R2, R10
+	BEQ	loop
+
+	// Input string is not 32-byte aligned. We calculate the
+	// syndrome value for the aligned 32 bytes block containing
+	// the first bytes and mask off the irrelevant part.
+	VLD1.P	(R3), [V1.B16, V2.B16]
+	SUB	$0x20, R9, R4
+	ADDS	R4, R2, R2
+	VCMEQ	V0.B16, V1.B16, V3.B16
+	VCMEQ	V0.B16, V2.B16, V4.B16
+	VAND	V5.B16, V3.B16, V3.B16
+	VAND	V5.B16, V4.B16, V4.B16
+	VADDP	V4.B16, V3.B16, V6.B16 // 256->128
+	VADDP	V6.B16, V6.B16, V6.B16 // 128->64
+	VMOV	V6.D[0], R6
+	// Clear the irrelevant lower bits
+	LSL	$1, R9, R4
+	LSR	R4, R6, R6
+	LSL	R4, R6, R6
+	// The first block can also be the last
+	BLS	masklast
+	// Have we found something already?
+	CBNZ	R6, tail
+
+loop:
+	VLD1.P	(R3), [V1.B16, V2.B16]
+	SUBS	$0x20, R2, R2
+	VCMEQ	V0.B16, V1.B16, V3.B16
+	VCMEQ	V0.B16, V2.B16, V4.B16
+	// If we're out of data we finish regardless of the result
+	BLS	end
+	// Use a fast check for the termination condition
+	VORR	V4.B16, V3.B16, V6.B16
+	VADDP	V6.D2, V6.D2, V6.D2
+	VMOV	V6.D[0], R6
+	// We're not out of data, loop if we haven't found the character
+	CBZ	R6, loop
+
+end:
+	// Termination condition found, let's calculate the syndrome value
+	VAND	V5.B16, V3.B16, V3.B16
+	VAND	V5.B16, V4.B16, V4.B16
+	VADDP	V4.B16, V3.B16, V6.B16
+	VADDP	V6.B16, V6.B16, V6.B16
+	VMOV	V6.D[0], R6
+	// Only do the clear for the last possible block with less than 32 bytes
+	// Condition flags come from SUBS in the loop
+	BHS	tail
+
+masklast:
+	// Clear the irrelevant upper bits
+	ADD	R9, R10, R4
+	AND	$0x1f, R4, R4
+	SUB	$0x20, R4, R4
+	NEG	R4<<1, R4
+	LSL	R4, R6, R6
+	LSR	R4, R6, R6
+
+tail:
+	// Check that we have found a character
+	CBZ	R6, fail
+	// Count the trailing zeros using bit reversing
+	RBIT	R6, R6
+	// Compensate the last post-increment
+	SUB	$0x20, R3, R3
+	// And count the leading zeros
+	CLZ	R6, R6
+	// R6 is twice the offset into the fragment
+	ADD	R6>>1, R3, R0
+	// Compute the offset result
+	SUB	R11, R0, R0
+	MOVD	R0, (R8)
+	RET
+
+fail:
+	MOVD	$-1, R0
+	MOVD	R0, (R8)
+	RET
diff --git a/contrib/go/_std_1.20/src/internal/bytealg/indexbyte_native.go b/contrib/go/_std_1.20/src/internal/bytealg/indexbyte_native.go
new file mode 100644
index 0000000000..c5bb2df5ea
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/bytealg/indexbyte_native.go
@@ -0,0 +1,13 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build 386 || amd64 || s390x || arm || arm64 || loong64 || ppc64 || ppc64le || mips || mipsle || mips64 || mips64le || riscv64 || wasm
+
+package bytealg
+
+//go:noescape
+func IndexByte(b []byte, c byte) int
+
+//go:noescape
+func IndexByteString(s string, c byte) int
diff --git a/contrib/go/_std_1.20/src/internal/bytealg/ya.make b/contrib/go/_std_1.20/src/internal/bytealg/ya.make
new file mode 100644
index 0000000000..16cb4d0eea
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/bytealg/ya.make
@@ -0,0 +1,35 @@
+GO_LIBRARY()
+
+SRCS(
+    bytealg.go
+    compare_native.go
+    count_native.go
+    equal_generic.go
+    equal_native.go
+    index_native.go
+    indexbyte_native.go
+)
+
+IF (ARCH_ARM64)
+    SRCS(
+        compare_arm64.s
+        count_arm64.s
+        equal_arm64.s
+        index_arm64.go
+        index_arm64.s
+        indexbyte_arm64.s
+    )
+ENDIF()
+
+IF (ARCH_X86_64)
+    SRCS(
+        compare_amd64.s
+        count_amd64.s
+        equal_amd64.s
+        index_amd64.go
+        index_amd64.s
+        indexbyte_amd64.s
+    )
+ENDIF()
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/coverage/calloc/batchcounteralloc.go b/contrib/go/_std_1.20/src/internal/coverage/calloc/batchcounteralloc.go
new file mode 100644
index 0000000000..2b6495d7a2
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/calloc/batchcounteralloc.go
@@ -0,0 +1,29 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package calloc
+
+// This package contains a simple "batch" allocator for allocating
+// coverage counters (slices of uint32 basically), for working with
+// coverage data files. Collections of counter arrays tend to all be
+// live/dead over the same time period, so a good fit for batch
+// allocation.
+
+type BatchCounterAlloc struct {
+	pool []uint32
+}
+
+func (ca *BatchCounterAlloc) AllocateCounters(n int) []uint32 {
+	const chunk = 8192
+	if n > cap(ca.pool) {
+		siz := chunk
+		if n > chunk {
+			siz = n
+		}
+		ca.pool = make([]uint32, siz)
+	}
+	rv := ca.pool[:n]
+	ca.pool = ca.pool[n:]
+	return rv
+}
diff --git a/contrib/go/_std_1.20/src/internal/coverage/calloc/ya.make b/contrib/go/_std_1.20/src/internal/coverage/calloc/ya.make
new file mode 100644
index 0000000000..96d1e6e2bc
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/calloc/ya.make
@@ -0,0 +1,7 @@
+GO_LIBRARY()
+
+SRCS(
+    batchcounteralloc.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/coverage/cformat/format.go b/contrib/go/_std_1.20/src/internal/coverage/cformat/format.go
new file mode 100644
index 0000000000..a8276ff124
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/cformat/format.go
@@ -0,0 +1,340 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cformat
+
+// This package provides apis for producing human-readable summaries
+// of coverage data (e.g. a coverage percentage for a given package or
+// set of packages) and for writing data in the legacy test format
+// emitted by "go test -coverprofile=<outfile>".
+//
+// The model for using these apis is to create a Formatter object,
+// then make a series of calls to SetPackage and AddUnit passing in
+// data read from coverage meta-data and counter-data files. E.g.
+//
+//		myformatter := cformat.NewFormatter()
+//		...
+//		for each package P in meta-data file: {
+//			myformatter.SetPackage(P)
+//			for each function F in P: {
+//				for each coverable unit U in F: {
+//					myformatter.AddUnit(U)
+//				}
+//			}
+//		}
+//		myformatter.EmitPercent(os.Stdout, "")
+//		myformatter.EmitTextual(somefile)
+//
+// These apis are linked into tests that are built with "-cover", and
+// called at the end of test execution to produce text output or
+// emit coverage percentages.
+
+import (
+	"fmt"
+	"internal/coverage"
+	"internal/coverage/cmerge"
+	"io"
+	"sort"
+	"text/tabwriter"
+)
+
+type Formatter struct {
+	// Maps import path to package state.
+	pm map[string]*pstate
+	// Records current package being visited.
+	pkg string
+	// Pointer to current package state.
+	p *pstate
+	// Counter mode.
+	cm coverage.CounterMode
+}
+
+// pstate records package-level coverage data state:
+// - a table of functions (file/fname/literal)
+// - a map recording the index/ID of each func encountered so far
+// - a table storing execution count for the coverable units in each func
+type pstate struct {
+	// slice of unique functions
+	funcs []fnfile
+	// maps function to index in slice above (index acts as function ID)
+	funcTable map[fnfile]uint32
+
+	// A table storing coverage counts for each coverable unit.
+	unitTable map[extcu]uint32
+}
+
+// extcu encapsulates a coverable unit within some function.
+type extcu struct {
+	fnfid uint32 // index into p.funcs slice
+	coverage.CoverableUnit
+}
+
+// fnfile is a function-name/file-name tuple.
+type fnfile struct {
+	file  string
+	fname string
+	lit   bool
+}
+
+func NewFormatter(cm coverage.CounterMode) *Formatter {
+	return &Formatter{
+		pm: make(map[string]*pstate),
+		cm: cm,
+	}
+}
+
+// SetPackage tells the formatter that we're about to visit the
+// coverage data for the package with the specified import path.
+// Note that it's OK to call SetPackage more than once with the
+// same import path; counter data values will be accumulated.
+func (fm *Formatter) SetPackage(importpath string) {
+	if importpath == fm.pkg {
+		return
+	}
+	fm.pkg = importpath
+	ps, ok := fm.pm[importpath]
+	if !ok {
+		ps = new(pstate)
+		fm.pm[importpath] = ps
+		ps.unitTable = make(map[extcu]uint32)
+		ps.funcTable = make(map[fnfile]uint32)
+	}
+	fm.p = ps
+}
+
+// AddUnit passes info on a single coverable unit (file, funcname,
+// literal flag, range of lines, and counter value) to the formatter.
+// Counter values will be accumulated where appropriate.
+func (fm *Formatter) AddUnit(file string, fname string, isfnlit bool, unit coverage.CoverableUnit, count uint32) {
+	if fm.p == nil {
+		panic("AddUnit invoked before SetPackage")
+	}
+	fkey := fnfile{file: file, fname: fname, lit: isfnlit}
+	idx, ok := fm.p.funcTable[fkey]
+	if !ok {
+		idx = uint32(len(fm.p.funcs))
+		fm.p.funcs = append(fm.p.funcs, fkey)
+		fm.p.funcTable[fkey] = idx
+	}
+	ukey := extcu{fnfid: idx, CoverableUnit: unit}
+	pcount := fm.p.unitTable[ukey]
+	var result uint32
+	if fm.cm == coverage.CtrModeSet {
+		if count != 0 || pcount != 0 {
+			result = 1
+		}
+	} else {
+		// Use saturating arithmetic.
+		result, _ = cmerge.SaturatingAdd(pcount, count)
+	}
+	fm.p.unitTable[ukey] = result
+}
+
+// sortUnits sorts a slice of extcu objects in a package according to
+// source position information (e.g. file and line). Note that we don't
+// include function name as part of the sorting criteria, the thinking
+// being that is better to provide things in the original source order.
+func (p *pstate) sortUnits(units []extcu) {
+	sort.Slice(units, func(i, j int) bool {
+		ui := units[i]
+		uj := units[j]
+		ifile := p.funcs[ui.fnfid].file
+		jfile := p.funcs[uj.fnfid].file
+		if ifile != jfile {
+			return ifile < jfile
+		}
+		// NB: not taking function literal flag into account here (no
+		// need, since other fields are guaranteed to be distinct).
+		if units[i].StLine != units[j].StLine {
+			return units[i].StLine < units[j].StLine
+		}
+		if units[i].EnLine != units[j].EnLine {
+			return units[i].EnLine < units[j].EnLine
+		}
+		if units[i].StCol != units[j].StCol {
+			return units[i].StCol < units[j].StCol
+		}
+		if units[i].EnCol != units[j].EnCol {
+			return units[i].EnCol < units[j].EnCol
+		}
+		return units[i].NxStmts < units[j].NxStmts
+	})
+}
+
+// EmitTextual writes the accumulated coverage data in the legacy
+// cmd/cover text format to the writer 'w'. We sort the data items by
+// importpath, source file, and line number before emitting (this sorting
+// is not explicitly mandated by the format, but seems like a good idea
+// for repeatable/deterministic dumps).
+func (fm *Formatter) EmitTextual(w io.Writer) error {
+	if fm.cm == coverage.CtrModeInvalid {
+		panic("internal error, counter mode unset")
+	}
+	if _, err := fmt.Fprintf(w, "mode: %s\n", fm.cm.String()); err != nil {
+		return err
+	}
+	pkgs := make([]string, 0, len(fm.pm))
+	for importpath := range fm.pm {
+		pkgs = append(pkgs, importpath)
+	}
+	sort.Strings(pkgs)
+	for _, importpath := range pkgs {
+		p := fm.pm[importpath]
+		units := make([]extcu, 0, len(p.unitTable))
+		for u := range p.unitTable {
+			units = append(units, u)
+		}
+		p.sortUnits(units)
+		for _, u := range units {
+			count := p.unitTable[u]
+			file := p.funcs[u.fnfid].file
+			if _, err := fmt.Fprintf(w, "%s:%d.%d,%d.%d %d %d\n",
+				file, u.StLine, u.StCol,
+				u.EnLine, u.EnCol, u.NxStmts, count); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+// EmitPercent writes out a "percentage covered" string to the writer 'w'.
+func (fm *Formatter) EmitPercent(w io.Writer, covpkgs string, noteEmpty bool) error {
+	pkgs := make([]string, 0, len(fm.pm))
+	for importpath := range fm.pm {
+		pkgs = append(pkgs, importpath)
+	}
+	sort.Strings(pkgs)
+	seenPkg := false
+	for _, importpath := range pkgs {
+		seenPkg = true
+		p := fm.pm[importpath]
+		var totalStmts, coveredStmts uint64
+		for unit, count := range p.unitTable {
+			nx := uint64(unit.NxStmts)
+			totalStmts += nx
+			if count != 0 {
+				coveredStmts += nx
+			}
+		}
+		if _, err := fmt.Fprintf(w, "\t%s\t", importpath); err != nil {
+			return err
+		}
+		if totalStmts == 0 {
+			if _, err := fmt.Fprintf(w, "coverage: [no statements]\n"); err != nil {
+				return err
+			}
+		} else {
+			if _, err := fmt.Fprintf(w, "coverage: %.1f%% of statements%s\n", 100*float64(coveredStmts)/float64(totalStmts), covpkgs); err != nil {
+				return err
+			}
+		}
+	}
+	if noteEmpty && !seenPkg {
+		if _, err := fmt.Fprintf(w, "coverage: [no statements]\n"); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// EmitFuncs writes out a function-level summary to the writer 'w'. A
+// note on handling function literals: although we collect coverage
+// data for unnamed literals, it probably does not make sense to
+// include them in the function summary since there isn't any good way
+// to name them (this is also consistent with the legacy cmd/cover
+// implementation). We do want to include their counts in the overall
+// summary however.
+func (fm *Formatter) EmitFuncs(w io.Writer) error {
+	if fm.cm == coverage.CtrModeInvalid {
+		panic("internal error, counter mode unset")
+	}
+	perc := func(covered, total uint64) float64 {
+		if total == 0 {
+			total = 1
+		}
+		return 100.0 * float64(covered) / float64(total)
+	}
+	tabber := tabwriter.NewWriter(w, 1, 8, 1, '\t', 0)
+	defer tabber.Flush()
+	allStmts := uint64(0)
+	covStmts := uint64(0)
+
+	pkgs := make([]string, 0, len(fm.pm))
+	for importpath := range fm.pm {
+		pkgs = append(pkgs, importpath)
+	}
+	sort.Strings(pkgs)
+
+	// Emit functions for each package, sorted by import path.
+	for _, importpath := range pkgs {
+		p := fm.pm[importpath]
+		if len(p.unitTable) == 0 {
+			continue
+		}
+		units := make([]extcu, 0, len(p.unitTable))
+		for u := range p.unitTable {
+			units = append(units, u)
+		}
+
+		// Within a package, sort the units, then walk through the
+		// sorted array. Each time we hit a new function, emit the
+		// summary entry for the previous function, then make one last
+		// emit call at the end of the loop.
+		p.sortUnits(units)
+		fname := ""
+		ffile := ""
+		flit := false
+		var fline uint32
+		var cstmts, tstmts uint64
+		captureFuncStart := func(u extcu) {
+			fname = p.funcs[u.fnfid].fname
+			ffile = p.funcs[u.fnfid].file
+			flit = p.funcs[u.fnfid].lit
+			fline = u.StLine
+		}
+		emitFunc := func(u extcu) error {
+			// Don't emit entries for function literals (see discussion
+			// in function header comment above).
+			if !flit {
+				if _, err := fmt.Fprintf(tabber, "%s:%d:\t%s\t%.1f%%\n",
+					ffile, fline, fname, perc(cstmts, tstmts)); err != nil {
+					return err
+				}
+			}
+			captureFuncStart(u)
+			allStmts += tstmts
+			covStmts += cstmts
+			tstmts = 0
+			cstmts = 0
+			return nil
+		}
+		for k, u := range units {
+			if k == 0 {
+				captureFuncStart(u)
+			} else {
+				if fname != p.funcs[u.fnfid].fname {
+					// New function; emit entry for previous one.
+					if err := emitFunc(u); err != nil {
+						return err
+					}
+				}
+			}
+			tstmts += uint64(u.NxStmts)
+			count := p.unitTable[u]
+			if count != 0 {
+				cstmts += uint64(u.NxStmts)
+			}
+		}
+		if err := emitFunc(extcu{}); err != nil {
+			return err
+		}
+	}
+	if _, err := fmt.Fprintf(tabber, "%s\t%s\t%.1f%%\n",
+		"total", "(statements)", perc(covStmts, allStmts)); err != nil {
+		return err
+	}
+	return nil
+}
diff --git a/contrib/go/_std_1.20/src/internal/coverage/cformat/ya.make b/contrib/go/_std_1.20/src/internal/coverage/cformat/ya.make
new file mode 100644
index 0000000000..2f71b28c69
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/cformat/ya.make
@@ -0,0 +1,7 @@
+GO_LIBRARY()
+
+SRCS(
+    format.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/coverage/cmddefs.go b/contrib/go/_std_1.20/src/internal/coverage/cmddefs.go
new file mode 100644
index 0000000000..b30c37a08f
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/cmddefs.go
@@ -0,0 +1,73 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package coverage
+
+// CoverPkgConfig is a bundle of information passed from the Go
+// command to the cover command during "go build -cover" runs. The
+// Go command creates and fills in a struct as below, then passes
+// file containing the encoded JSON for the struct to the "cover"
+// tool when instrumenting the source files in a Go package.
+type CoverPkgConfig struct {
+	// File into which cmd/cover should emit summary info
+	// when instrumentation is complete.
+	OutConfig string
+
+	// Import path for the package being instrumented.
+	PkgPath string
+
+	// Package name.
+	PkgName string
+
+	// Instrumentation granularity: one of "perfunc" or "perblock" (default)
+	Granularity string
+
+	// Module path for this package (empty if no go.mod in use)
+	ModulePath string
+
+	// Local mode indicates we're doing a coverage build or test of a
+	// package selected via local import path, e.g. "./..." or
+	// "./foo/bar" as opposed to a non-relative import path. See the
+	// corresponding field in cmd/go's PackageInternal struct for more
+	// info.
+	Local bool
+}
+
+// CoverFixupConfig contains annotations/notes generated by the
+// cmd/cover tool (during instrumentation) to be passed on to the
+// compiler when the instrumented code is compiled. The cmd/cover tool
+// creates a struct of this type, JSON-encodes it, and emits the
+// result to a file, which the Go command then passes to the compiler
+// when the instrumented package is built.
+type CoverFixupConfig struct {
+	// Name of the variable (created by cmd/cover) containing the
+	// encoded meta-data for the package.
+	MetaVar string
+
+	// Length of the meta-data.
+	MetaLen int
+
+	// Hash computed by cmd/cover of the meta-data.
+	MetaHash string
+
+	// Instrumentation strategy. For now this is always set to
+	// "normal", but in the future we may add new values (for example,
+	// if panic paths are instrumented, or if the instrumenter
+	// eliminates redundant counters).
+	Strategy string
+
+	// Prefix assigned to the names of counter variables generated
+	// during instrumentation by cmd/cover.
+	CounterPrefix string
+
+	// Name chosen for the package ID variable generated during
+	// instrumentation.
+	PkgIdVar string
+
+	// Counter mode (e.g. set/count/atomic)
+	CounterMode string
+
+	// Counter granularity (perblock or perfunc).
+	CounterGranularity string
+}
diff --git a/contrib/go/_std_1.20/src/internal/coverage/cmerge/merge.go b/contrib/go/_std_1.20/src/internal/coverage/cmerge/merge.go
new file mode 100644
index 0000000000..c482b8bfa8
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/cmerge/merge.go
@@ -0,0 +1,104 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cmerge
+
+// package cmerge provides a few small utility APIs for helping
+// with merging of counter data for a given function.
+
+import (
+	"fmt"
+	"internal/coverage"
+	"math"
+)
+
+// Merger provides state and methods to help manage the process of
+// merging together coverage counter data for a given function, for
+// tools that need to implicitly merge counter as they read multiple
+// coverage counter data files.
+type Merger struct {
+	cmode    coverage.CounterMode
+	cgran    coverage.CounterGranularity
+	overflow bool
+}
+
+// MergeCounters takes the counter values in 'src' and merges them
+// into 'dst' according to the correct counter mode.
+func (m *Merger) MergeCounters(dst, src []uint32) (error, bool) {
+	if len(src) != len(dst) {
+		return fmt.Errorf("merging counters: len(dst)=%d len(src)=%d", len(dst), len(src)), false
+	}
+	if m.cmode == coverage.CtrModeSet {
+		for i := 0; i < len(src); i++ {
+			if src[i] != 0 {
+				dst[i] = 1
+			}
+		}
+	} else {
+		for i := 0; i < len(src); i++ {
+			dst[i] = m.SaturatingAdd(dst[i], src[i])
+		}
+	}
+	ovf := m.overflow
+	m.overflow = false
+	return nil, ovf
+}
+
+// Saturating add does a saturating addition of 'dst' and 'src',
+// returning added value or math.MaxUint32 if there is an overflow.
+// Overflows are recorded in case the client needs to track them.
+func (m *Merger) SaturatingAdd(dst, src uint32) uint32 {
+	result, overflow := SaturatingAdd(dst, src)
+	if overflow {
+		m.overflow = true
+	}
+	return result
+}
+
+// Saturating add does a saturing addition of 'dst' and 'src',
+// returning added value or math.MaxUint32 plus an overflow flag.
+func SaturatingAdd(dst, src uint32) (uint32, bool) {
+	d, s := uint64(dst), uint64(src)
+	sum := d + s
+	overflow := false
+	if uint64(uint32(sum)) != sum {
+		overflow = true
+		sum = math.MaxUint32
+	}
+	return uint32(sum), overflow
+}
+
+// SetModeAndGranularity records the counter mode and granularity for
+// the current merge. In the specific case of merging across coverage
+// data files from different binaries, where we're combining data from
+// more than one meta-data file, we need to check for mode/granularity
+// clashes.
+func (cm *Merger) SetModeAndGranularity(mdf string, cmode coverage.CounterMode, cgran coverage.CounterGranularity) error {
+	// Collect counter mode and granularity so as to detect clashes.
+	if cm.cmode != coverage.CtrModeInvalid {
+		if cm.cmode != cmode {
+			return fmt.Errorf("counter mode clash while reading meta-data file %s: previous file had %s, new file has %s", mdf, cm.cmode.String(), cmode.String())
+		}
+		if cm.cgran != cgran {
+			return fmt.Errorf("counter granularity clash while reading meta-data file %s: previous file had %s, new file has %s", mdf, cm.cgran.String(), cgran.String())
+		}
+	}
+	cm.cmode = cmode
+	cm.cgran = cgran
+	return nil
+}
+
+func (cm *Merger) ResetModeAndGranularity() {
+	cm.cmode = coverage.CtrModeInvalid
+	cm.cgran = coverage.CtrGranularityInvalid
+	cm.overflow = false
+}
+
+func (cm *Merger) Mode() coverage.CounterMode {
+	return cm.cmode
+}
+
+func (cm *Merger) Granularity() coverage.CounterGranularity {
+	return cm.cgran
+}
diff --git a/contrib/go/_std_1.20/src/internal/coverage/cmerge/ya.make b/contrib/go/_std_1.20/src/internal/coverage/cmerge/ya.make
new file mode 100644
index 0000000000..3014b57456
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/cmerge/ya.make
@@ -0,0 +1,7 @@
+GO_LIBRARY()
+
+SRCS(
+    merge.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/coverage/decodecounter/decodecounterfile.go b/contrib/go/_std_1.20/src/internal/coverage/decodecounter/decodecounterfile.go
new file mode 100644
index 0000000000..fce060aaba
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/decodecounter/decodecounterfile.go
@@ -0,0 +1,373 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package decodecounter
+
+import (
+	"encoding/binary"
+	"fmt"
+	"internal/coverage"
+	"internal/coverage/slicereader"
+	"internal/coverage/stringtab"
+	"io"
+	"os"
+	"strconv"
+	"unsafe"
+)
+
+// This file contains helpers for reading counter data files created
+// during the executions of a coverage-instrumented binary.
+
+type CounterDataReader struct {
+	stab     *stringtab.Reader
+	args     map[string]string
+	osargs   []string
+	goarch   string // GOARCH setting from run that produced counter data
+	goos     string // GOOS setting from run that produced counter data
+	mr       io.ReadSeeker
+	hdr      coverage.CounterFileHeader
+	ftr      coverage.CounterFileFooter
+	shdr     coverage.CounterSegmentHeader
+	u32b     []byte
+	u8b      []byte
+	fcnCount uint32
+	segCount uint32
+	debug    bool
+}
+
+func NewCounterDataReader(fn string, rs io.ReadSeeker) (*CounterDataReader, error) {
+	cdr := &CounterDataReader{
+		mr:   rs,
+		u32b: make([]byte, 4),
+		u8b:  make([]byte, 1),
+	}
+	// Read header
+	if err := binary.Read(rs, binary.LittleEndian, &cdr.hdr); err != nil {
+		return nil, err
+	}
+	if cdr.debug {
+		fmt.Fprintf(os.Stderr, "=-= counter file header: %+v\n", cdr.hdr)
+	}
+	if !checkMagic(cdr.hdr.Magic) {
+		return nil, fmt.Errorf("invalid magic string: not a counter data file")
+	}
+	if cdr.hdr.Version > coverage.CounterFileVersion {
+		return nil, fmt.Errorf("version data incompatibility: reader is %d data is %d", coverage.CounterFileVersion, cdr.hdr.Version)
+	}
+
+	// Read footer.
+	if err := cdr.readFooter(); err != nil {
+		return nil, err
+	}
+	// Seek back to just past the file header.
+	hsz := int64(unsafe.Sizeof(cdr.hdr))
+	if _, err := cdr.mr.Seek(hsz, io.SeekStart); err != nil {
+		return nil, err
+	}
+	// Read preamble for first segment.
+	if err := cdr.readSegmentPreamble(); err != nil {
+		return nil, err
+	}
+	return cdr, nil
+}
+
+func checkMagic(v [4]byte) bool {
+	g := coverage.CovCounterMagic
+	return v[0] == g[0] && v[1] == g[1] && v[2] == g[2] && v[3] == g[3]
+}
+
+func (cdr *CounterDataReader) readFooter() error {
+	ftrSize := int64(unsafe.Sizeof(cdr.ftr))
+	if _, err := cdr.mr.Seek(-ftrSize, io.SeekEnd); err != nil {
+		return err
+	}
+	if err := binary.Read(cdr.mr, binary.LittleEndian, &cdr.ftr); err != nil {
+		return err
+	}
+	if !checkMagic(cdr.ftr.Magic) {
+		return fmt.Errorf("invalid magic string (not a counter data file)")
+	}
+	if cdr.ftr.NumSegments == 0 {
+		return fmt.Errorf("invalid counter data file (no segments)")
+	}
+	return nil
+}
+
+// readSegmentPreamble reads and consumes the segment header, segment string
+// table, and segment args table.
+func (cdr *CounterDataReader) readSegmentPreamble() error {
+	// Read segment header.
+	if err := binary.Read(cdr.mr, binary.LittleEndian, &cdr.shdr); err != nil {
+		return err
+	}
+	if cdr.debug {
+		fmt.Fprintf(os.Stderr, "=-= read counter segment header: %+v", cdr.shdr)
+		fmt.Fprintf(os.Stderr, " FcnEntries=0x%x StrTabLen=0x%x ArgsLen=0x%x\n",
+			cdr.shdr.FcnEntries, cdr.shdr.StrTabLen, cdr.shdr.ArgsLen)
+	}
+
+	// Read string table and args.
+	if err := cdr.readStringTable(); err != nil {
+		return err
+	}
+	if err := cdr.readArgs(); err != nil {
+		return err
+	}
+	// Seek past any padding to bring us up to a 4-byte boundary.
+	if of, err := cdr.mr.Seek(0, io.SeekCurrent); err != nil {
+		return err
+	} else {
+		rem := of % 4
+		if rem != 0 {
+			pad := 4 - rem
+			if _, err := cdr.mr.Seek(pad, io.SeekCurrent); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+func (cdr *CounterDataReader) readStringTable() error {
+	b := make([]byte, cdr.shdr.StrTabLen)
+	nr, err := cdr.mr.Read(b)
+	if err != nil {
+		return err
+	}
+	if nr != int(cdr.shdr.StrTabLen) {
+		return fmt.Errorf("error: short read on string table")
+	}
+	slr := slicereader.NewReader(b, false /* not readonly */)
+	cdr.stab = stringtab.NewReader(slr)
+	cdr.stab.Read()
+	return nil
+}
+
+func (cdr *CounterDataReader) readArgs() error {
+	b := make([]byte, cdr.shdr.ArgsLen)
+	nr, err := cdr.mr.Read(b)
+	if err != nil {
+		return err
+	}
+	if nr != int(cdr.shdr.ArgsLen) {
+		return fmt.Errorf("error: short read on args table")
+	}
+	slr := slicereader.NewReader(b, false /* not readonly */)
+	sget := func() (string, error) {
+		kidx := slr.ReadULEB128()
+		if int(kidx) >= cdr.stab.Entries() {
+			return "", fmt.Errorf("malformed string table ref")
+		}
+		return cdr.stab.Get(uint32(kidx)), nil
+	}
+	nents := slr.ReadULEB128()
+	cdr.args = make(map[string]string, int(nents))
+	for i := uint64(0); i < nents; i++ {
+		k, errk := sget()
+		if errk != nil {
+			return errk
+		}
+		v, errv := sget()
+		if errv != nil {
+			return errv
+		}
+		if _, ok := cdr.args[k]; ok {
+			return fmt.Errorf("malformed args table")
+		}
+		cdr.args[k] = v
+	}
+	if argcs, ok := cdr.args["argc"]; ok {
+		argc, err := strconv.Atoi(argcs)
+		if err != nil {
+			return fmt.Errorf("malformed argc in counter data file args section")
+		}
+		cdr.osargs = make([]string, 0, argc)
+		for i := 0; i < argc; i++ {
+			arg := cdr.args[fmt.Sprintf("argv%d", i)]
+			cdr.osargs = append(cdr.osargs, arg)
+		}
+	}
+	if goos, ok := cdr.args["GOOS"]; ok {
+		cdr.goos = goos
+	}
+	if goarch, ok := cdr.args["GOARCH"]; ok {
+		cdr.goarch = goarch
+	}
+	return nil
+}
+
+// OsArgs returns the program arguments (saved from os.Args during
+// the run of the instrumented binary) read from the counter
+// data file. Not all coverage data files will have os.Args values;
+// for example, if a data file is produced by merging coverage
+// data from two distinct runs, no os args will be available (an
+// empty list is returned).
+func (cdr *CounterDataReader) OsArgs() []string {
+	return cdr.osargs
+}
+
+// Goos returns the GOOS setting in effect for the "-cover" binary
+// that produced this counter data file. The GOOS value may be
+// empty in the case where the counter data file was produced
+// from a merge in which more than one GOOS value was present.
+func (cdr *CounterDataReader) Goos() string {
+	return cdr.goos
+}
+
+// Goarch returns the GOARCH setting in effect for the "-cover" binary
+// that produced this counter data file. The GOARCH value may be
+// empty in the case where the counter data file was produced
+// from a merge in which more than one GOARCH value was present.
+func (cdr *CounterDataReader) Goarch() string {
+	return cdr.goarch
+}
+
+// FuncPayload encapsulates the counter data payload for a single
+// function as read from a counter data file.
+type FuncPayload struct {
+	PkgIdx   uint32
+	FuncIdx  uint32
+	Counters []uint32
+}
+
+// NumSegments returns the number of execution segments in the file.
+func (cdr *CounterDataReader) NumSegments() uint32 {
+	return cdr.ftr.NumSegments
+}
+
+// BeginNextSegment sets up the the reader to read the next segment,
+// returning TRUE if we do have another segment to read, or FALSE
+// if we're done with all the segments (also an error if
+// something went wrong).
+func (cdr *CounterDataReader) BeginNextSegment() (bool, error) {
+	if cdr.segCount >= cdr.ftr.NumSegments {
+		return false, nil
+	}
+	cdr.segCount++
+	cdr.fcnCount = 0
+	// Seek past footer from last segment.
+	ftrSize := int64(unsafe.Sizeof(cdr.ftr))
+	if _, err := cdr.mr.Seek(ftrSize, io.SeekCurrent); err != nil {
+		return false, err
+	}
+	// Read preamble for this segment.
+	if err := cdr.readSegmentPreamble(); err != nil {
+		return false, err
+	}
+	return true, nil
+}
+
+// NumFunctionsInSegment returns the number of live functions
+// in the currently selected segment.
+func (cdr *CounterDataReader) NumFunctionsInSegment() uint32 {
+	return uint32(cdr.shdr.FcnEntries)
+}
+
+const supportDeadFunctionsInCounterData = false
+
+// NextFunc reads data for the next function in this current segment
+// into "p", returning TRUE if the read was successful or FALSE
+// if we've read all the functions already (also an error if
+// something went wrong with the read or we hit a premature
+// EOF).
+func (cdr *CounterDataReader) NextFunc(p *FuncPayload) (bool, error) {
+	if cdr.fcnCount >= uint32(cdr.shdr.FcnEntries) {
+		return false, nil
+	}
+	cdr.fcnCount++
+	var rdu32 func() (uint32, error)
+	if cdr.hdr.CFlavor == coverage.CtrULeb128 {
+		rdu32 = func() (uint32, error) {
+			var shift uint
+			var value uint64
+			for {
+				_, err := cdr.mr.Read(cdr.u8b)
+				if err != nil {
+					return 0, err
+				}
+				b := cdr.u8b[0]
+				value |= (uint64(b&0x7F) << shift)
+				if b&0x80 == 0 {
+					break
+				}
+				shift += 7
+			}
+			return uint32(value), nil
+		}
+	} else if cdr.hdr.CFlavor == coverage.CtrRaw {
+		if cdr.hdr.BigEndian {
+			rdu32 = func() (uint32, error) {
+				n, err := cdr.mr.Read(cdr.u32b)
+				if err != nil {
+					return 0, err
+				}
+				if n != 4 {
+					return 0, io.EOF
+				}
+				return binary.BigEndian.Uint32(cdr.u32b), nil
+			}
+		} else {
+			rdu32 = func() (uint32, error) {
+				n, err := cdr.mr.Read(cdr.u32b)
+				if err != nil {
+					return 0, err
+				}
+				if n != 4 {
+					return 0, io.EOF
+				}
+				return binary.LittleEndian.Uint32(cdr.u32b), nil
+			}
+		}
+	} else {
+		panic("internal error: unknown counter flavor")
+	}
+
+	// Alternative/experimental path: one way we could handling writing
+	// out counter data would be to just memcpy the counter segment
+	// out to a file, meaning that a region in the counter memory
+	// corresponding to a dead (never-executed) function would just be
+	// zeroes. The code path below handles this case.
+	var nc uint32
+	var err error
+	if supportDeadFunctionsInCounterData {
+		for {
+			nc, err = rdu32()
+			if err == io.EOF {
+				return false, io.EOF
+			} else if err != nil {
+				break
+			}
+			if nc != 0 {
+				break
+			}
+		}
+	} else {
+		nc, err = rdu32()
+	}
+	if err != nil {
+		return false, err
+	}
+
+	// Read package and func indices.
+	p.PkgIdx, err = rdu32()
+	if err != nil {
+		return false, err
+	}
+	p.FuncIdx, err = rdu32()
+	if err != nil {
+		return false, err
+	}
+	if cap(p.Counters) < 1024 {
+		p.Counters = make([]uint32, 0, 1024)
+	}
+	p.Counters = p.Counters[:0]
+	for i := uint32(0); i < nc; i++ {
+		v, err := rdu32()
+		if err != nil {
+			return false, err
+		}
+		p.Counters = append(p.Counters, v)
+	}
+	return true, nil
+}
diff --git a/contrib/go/_std_1.20/src/internal/coverage/decodecounter/ya.make b/contrib/go/_std_1.20/src/internal/coverage/decodecounter/ya.make
new file mode 100644
index 0000000000..d761ccb0cf
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/decodecounter/ya.make
@@ -0,0 +1,7 @@
+GO_LIBRARY()
+
+SRCS(
+    decodecounterfile.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/coverage/decodemeta/decode.go b/contrib/go/_std_1.20/src/internal/coverage/decodemeta/decode.go
new file mode 100644
index 0000000000..71f1c567ab
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/decodemeta/decode.go
@@ -0,0 +1,128 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package decodemeta
+
+// This package contains APIs and helpers for decoding a single package's
+// meta data "blob" emitted by the compiler when coverage instrumentation
+// is turned on.
+
+import (
+	"encoding/binary"
+	"fmt"
+	"internal/coverage"
+	"internal/coverage/slicereader"
+	"internal/coverage/stringtab"
+	"os"
+)
+
+// See comments in the encodecovmeta package for details on the format.
+
+type CoverageMetaDataDecoder struct {
+	r      *slicereader.Reader
+	hdr    coverage.MetaSymbolHeader
+	strtab *stringtab.Reader
+	tmp    []byte
+	debug  bool
+}
+
+func NewCoverageMetaDataDecoder(b []byte, readonly bool) (*CoverageMetaDataDecoder, error) {
+	slr := slicereader.NewReader(b, readonly)
+	x := &CoverageMetaDataDecoder{
+		r:   slr,
+		tmp: make([]byte, 0, 256),
+	}
+	if err := x.readHeader(); err != nil {
+		return nil, err
+	}
+	if err := x.readStringTable(); err != nil {
+		return nil, err
+	}
+	return x, nil
+}
+
+func (d *CoverageMetaDataDecoder) readHeader() error {
+	if err := binary.Read(d.r, binary.LittleEndian, &d.hdr); err != nil {
+		return err
+	}
+	if d.debug {
+		fmt.Fprintf(os.Stderr, "=-= after readHeader: %+v\n", d.hdr)
+	}
+	return nil
+}
+
+func (d *CoverageMetaDataDecoder) readStringTable() error {
+	// Seek to the correct location to read the string table.
+	stringTableLocation := int64(coverage.CovMetaHeaderSize + 4*d.hdr.NumFuncs)
+	d.r.SeekTo(stringTableLocation)
+
+	// Read the table itself.
+	d.strtab = stringtab.NewReader(d.r)
+	d.strtab.Read()
+	return nil
+}
+
+func (d *CoverageMetaDataDecoder) PackagePath() string {
+	return d.strtab.Get(d.hdr.PkgPath)
+}
+
+func (d *CoverageMetaDataDecoder) PackageName() string {
+	return d.strtab.Get(d.hdr.PkgName)
+}
+
+func (d *CoverageMetaDataDecoder) ModulePath() string {
+	return d.strtab.Get(d.hdr.ModulePath)
+}
+
+func (d *CoverageMetaDataDecoder) NumFuncs() uint32 {
+	return d.hdr.NumFuncs
+}
+
+// ReadFunc reads the coverage meta-data for the function with index
+// 'findex', filling it into the FuncDesc pointed to by 'f'.
+func (d *CoverageMetaDataDecoder) ReadFunc(fidx uint32, f *coverage.FuncDesc) error {
+	if fidx >= d.hdr.NumFuncs {
+		return fmt.Errorf("illegal function index")
+	}
+
+	// Seek to the correct location to read the function offset and read it.
+	funcOffsetLocation := int64(coverage.CovMetaHeaderSize + 4*fidx)
+	d.r.SeekTo(funcOffsetLocation)
+	foff := d.r.ReadUint32()
+
+	// Check assumptions
+	if foff < uint32(funcOffsetLocation) || foff > d.hdr.Length {
+		return fmt.Errorf("malformed func offset %d", foff)
+	}
+
+	// Seek to the correct location to read the function.
+	d.r.SeekTo(int64(foff))
+
+	// Preamble containing number of units, file, and function.
+	numUnits := uint32(d.r.ReadULEB128())
+	fnameidx := uint32(d.r.ReadULEB128())
+	fileidx := uint32(d.r.ReadULEB128())
+
+	f.Srcfile = d.strtab.Get(fileidx)
+	f.Funcname = d.strtab.Get(fnameidx)
+
+	// Now the units
+	f.Units = f.Units[:0]
+	if cap(f.Units) < int(numUnits) {
+		f.Units = make([]coverage.CoverableUnit, 0, numUnits)
+	}
+	for k := uint32(0); k < numUnits; k++ {
+		f.Units = append(f.Units,
+			coverage.CoverableUnit{
+				StLine:  uint32(d.r.ReadULEB128()),
+				StCol:   uint32(d.r.ReadULEB128()),
+				EnLine:  uint32(d.r.ReadULEB128()),
+				EnCol:   uint32(d.r.ReadULEB128()),
+				NxStmts: uint32(d.r.ReadULEB128()),
+			})
+	}
+	lit := d.r.ReadULEB128()
+	f.Lit = lit != 0
+	return nil
+}
diff --git a/contrib/go/_std_1.20/src/internal/coverage/decodemeta/decodefile.go b/contrib/go/_std_1.20/src/internal/coverage/decodemeta/decodefile.go
new file mode 100644
index 0000000000..6580dd5402
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/decodemeta/decodefile.go
@@ -0,0 +1,223 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package decodemeta
+
+// This package contains APIs and helpers for reading and decoding
+// meta-data output files emitted by the runtime when a
+// coverage-instrumented binary executes. A meta-data file contains
+// top-level info (counter mode, number of packages) and then a
+// separate self-contained meta-data section for each Go package.
+
+import (
+	"bufio"
+	"crypto/md5"
+	"encoding/binary"
+	"fmt"
+	"internal/coverage"
+	"internal/coverage/slicereader"
+	"internal/coverage/stringtab"
+	"io"
+	"os"
+)
+
+// CoverageMetaFileReader provides state and methods for reading
+// a meta-data file from a code coverage run.
+type CoverageMetaFileReader struct {
+	f          *os.File
+	hdr        coverage.MetaFileHeader
+	tmp        []byte
+	pkgOffsets []uint64
+	pkgLengths []uint64
+	strtab     *stringtab.Reader
+	fileRdr    *bufio.Reader
+	fileView   []byte
+	debug      bool
+}
+
+// NewCoverageMetaFileReader returns a new helper object for reading
+// the coverage meta-data output file 'f'. The param 'fileView' is a
+// read-only slice containing the contents of 'f' obtained by mmap'ing
+// the file read-only; 'fileView' may be nil, in which case the helper
+// will read the contents of the file using regular file Read
+// operations.
+func NewCoverageMetaFileReader(f *os.File, fileView []byte) (*CoverageMetaFileReader, error) {
+	r := &CoverageMetaFileReader{
+		f:        f,
+		fileView: fileView,
+		tmp:      make([]byte, 256),
+	}
+
+	if err := r.readFileHeader(); err != nil {
+		return nil, err
+	}
+	return r, nil
+}
+
+func (r *CoverageMetaFileReader) readFileHeader() error {
+	var err error
+
+	r.fileRdr = bufio.NewReader(r.f)
+
+	// Read file header.
+	if err := binary.Read(r.fileRdr, binary.LittleEndian, &r.hdr); err != nil {
+		return err
+	}
+
+	// Verify magic string
+	m := r.hdr.Magic
+	g := coverage.CovMetaMagic
+	if m[0] != g[0] || m[1] != g[1] || m[2] != g[2] || m[3] != g[3] {
+		return fmt.Errorf("invalid meta-data file magic string")
+	}
+
+	// Vet the version. If this is a meta-data file from the future,
+	// we won't be able to read it.
+	if r.hdr.Version > coverage.MetaFileVersion {
+		return fmt.Errorf("meta-data file withn unknown version %d (expected %d)", r.hdr.Version, coverage.MetaFileVersion)
+	}
+
+	// Read package offsets for good measure
+	r.pkgOffsets = make([]uint64, r.hdr.Entries)
+	for i := uint64(0); i < r.hdr.Entries; i++ {
+		if r.pkgOffsets[i], err = r.rdUint64(); err != nil {
+			return err
+		}
+		if r.pkgOffsets[i] > r.hdr.TotalLength {
+			return fmt.Errorf("insane pkg offset %d: %d > totlen %d",
+				i, r.pkgOffsets[i], r.hdr.TotalLength)
+		}
+	}
+	r.pkgLengths = make([]uint64, r.hdr.Entries)
+	for i := uint64(0); i < r.hdr.Entries; i++ {
+		if r.pkgLengths[i], err = r.rdUint64(); err != nil {
+			return err
+		}
+		if r.pkgLengths[i] > r.hdr.TotalLength {
+			return fmt.Errorf("insane pkg length %d: %d > totlen %d",
+				i, r.pkgLengths[i], r.hdr.TotalLength)
+		}
+	}
+
+	// Read string table.
+	b := make([]byte, r.hdr.StrTabLength)
+	nr, err := r.fileRdr.Read(b)
+	if err != nil {
+		return err
+	}
+	if nr != int(r.hdr.StrTabLength) {
+		return fmt.Errorf("error: short read on string table")
+	}
+	slr := slicereader.NewReader(b, false /* not readonly */)
+	r.strtab = stringtab.NewReader(slr)
+	r.strtab.Read()
+
+	if r.debug {
+		fmt.Fprintf(os.Stderr, "=-= read-in header is: %+v\n", *r)
+	}
+
+	return nil
+}
+
+func (r *CoverageMetaFileReader) rdUint64() (uint64, error) {
+	r.tmp = r.tmp[:0]
+	r.tmp = append(r.tmp, make([]byte, 8)...)
+	n, err := r.fileRdr.Read(r.tmp)
+	if err != nil {
+		return 0, err
+	}
+	if n != 8 {
+		return 0, fmt.Errorf("premature end of file on read")
+	}
+	v := binary.LittleEndian.Uint64(r.tmp)
+	return v, nil
+}
+
+// NumPackages returns the number of packages for which this file
+// contains meta-data.
+func (r *CoverageMetaFileReader) NumPackages() uint64 {
+	return r.hdr.Entries
+}
+
+// CounterMode returns the counter mode (set, count, atomic) used
+// when building for coverage for the program that produce this
+// meta-data file.
+func (r *CoverageMetaFileReader) CounterMode() coverage.CounterMode {
+	return r.hdr.CMode
+}
+
+// CounterMode returns the counter granularity (single counter per
+// function, or counter per block) selected when building for coverage
+// for the program that produce this meta-data file.
+func (r *CoverageMetaFileReader) CounterGranularity() coverage.CounterGranularity {
+	return r.hdr.CGranularity
+}
+
+// FileHash returns the hash computed for all of the package meta-data
+// blobs. Coverage counter data files refer to this hash, and the
+// hash will be encoded into the meta-data file name.
+func (r *CoverageMetaFileReader) FileHash() [16]byte {
+	return r.hdr.MetaFileHash
+}
+
+// GetPackageDecoder requests a decoder object for the package within
+// the meta-data file whose index is 'pkIdx'. If the
+// CoverageMetaFileReader was set up with a read-only file view, a
+// pointer into that file view will be returned, otherwise the buffer
+// 'payloadbuf' will be written to (or if it is not of sufficient
+// size, a new buffer will be allocated). Return value is the decoder,
+// a byte slice with the encoded meta-data, and an error.
+func (r *CoverageMetaFileReader) GetPackageDecoder(pkIdx uint32, payloadbuf []byte) (*CoverageMetaDataDecoder, []byte, error) {
+	pp, err := r.GetPackagePayload(pkIdx, payloadbuf)
+	if r.debug {
+		fmt.Fprintf(os.Stderr, "=-= pkidx=%d payload length is %d hash=%s\n",
+			pkIdx, len(pp), fmt.Sprintf("%x", md5.Sum(pp)))
+	}
+	if err != nil {
+		return nil, nil, err
+	}
+	mdd, err := NewCoverageMetaDataDecoder(pp, r.fileView != nil)
+	if err != nil {
+		return nil, nil, err
+	}
+	return mdd, pp, nil
+}
+
+// GetPackagePayload returns the raw (encoded) meta-data payload for the
+// package with index 'pkIdx'. As with GetPackageDecoder, if the
+// CoverageMetaFileReader was set up with a read-only file view, a
+// pointer into that file view will be returned, otherwise the buffer
+// 'payloadbuf' will be written to (or if it is not of sufficient
+// size, a new buffer will be allocated). Return value is the decoder,
+// a byte slice with the encoded meta-data, and an error.
+func (r *CoverageMetaFileReader) GetPackagePayload(pkIdx uint32, payloadbuf []byte) ([]byte, error) {
+
+	// Determine correct offset/length.
+	if uint64(pkIdx) >= r.hdr.Entries {
+		return nil, fmt.Errorf("GetPackagePayload: illegal pkg index %d", pkIdx)
+	}
+	off := r.pkgOffsets[pkIdx]
+	len := r.pkgLengths[pkIdx]
+
+	if r.debug {
+		fmt.Fprintf(os.Stderr, "=-= for pk %d, off=%d len=%d\n", pkIdx, off, len)
+	}
+
+	if r.fileView != nil {
+		return r.fileView[off : off+len], nil
+	}
+
+	payload := payloadbuf[:0]
+	if cap(payload) < int(len) {
+		payload = make([]byte, 0, len)
+	}
+	payload = append(payload, make([]byte, len)...)
+	if _, err := r.f.Seek(int64(off), io.SeekStart); err != nil {
+		return nil, err
+	}
+	if _, err := io.ReadFull(r.f, payload); err != nil {
+		return nil, err
+	}
+	return payload, nil
+}
diff --git a/contrib/go/_std_1.20/src/internal/coverage/decodemeta/ya.make b/contrib/go/_std_1.20/src/internal/coverage/decodemeta/ya.make
new file mode 100644
index 0000000000..60b27ce04e
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/decodemeta/ya.make
@@ -0,0 +1,8 @@
+GO_LIBRARY()
+
+SRCS(
+    decode.go
+    decodefile.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/coverage/defs.go b/contrib/go/_std_1.20/src/internal/coverage/defs.go
new file mode 100644
index 0000000000..4a41f57efd
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/defs.go
@@ -0,0 +1,374 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package coverage
+
+// Types and constants related to the output files files written
+// by code coverage tooling. When a coverage-instrumented binary
+// is run, it emits two output files: a meta-data output file, and
+// a counter data output file.
+
+//.....................................................................
+//
+// Meta-data definitions:
+//
+// The meta-data file is composed of a file header, a series of
+// meta-data blobs/sections (one per instrumented package), and an offsets
+// area storing the offsets of each section. Format of the meta-data
+// file looks like:
+//
+// --header----------
+//  | magic: [4]byte magic string
+//  | version
+//  | total length of meta-data file in bytes
+//  | numPkgs: number of package entries in file
+//  | hash: [16]byte hash of entire meta-data payload
+//  | offset to string table section
+//  | length of string table
+//  | number of entries in string table
+//  | counter mode
+//  | counter granularity
+//  --package offsets table------
+//  <offset to pkg 0>
+//  <offset to pkg 1>
+//  ...
+//  --package lengths table------
+//  <length of pkg 0>
+//  <length of pkg 1>
+//  ...
+//  --string table------
+//  <uleb128 len> 8
+//  <data> "somestring"
+//  ...
+//  --package payloads------
+//  <meta-symbol for pkg 0>
+//  <meta-symbol for pkg 1>
+//  ...
+//
+// Each package payload is a stand-alone blob emitted by the compiler,
+// and does not depend on anything else in the meta-data file. In
+// particular, each blob has it's own string table. Note that the
+// file-level string table is expected to be very short (most strings
+// will be in the meta-data blobs themselves).
+
+// CovMetaMagic holds the magic string for a meta-data file.
+var CovMetaMagic = [4]byte{'\x00', '\x63', '\x76', '\x6d'}
+
+// MetaFilePref is a prefix used when emitting meta-data files; these
+// files are of the form "covmeta.<hash>", where hash is a hash
+// computed from the hashes of all the package meta-data symbols in
+// the program.
+const MetaFilePref = "covmeta"
+
+// MetaFileVersion contains the current (most recent) meta-data file version.
+const MetaFileVersion = 1
+
+// MetaFileHeader stores file header information for a meta-data file.
+type MetaFileHeader struct {
+	Magic        [4]byte
+	Version      uint32
+	TotalLength  uint64
+	Entries      uint64
+	MetaFileHash [16]byte
+	StrTabOffset uint32
+	StrTabLength uint32
+	CMode        CounterMode
+	CGranularity CounterGranularity
+	_            [6]byte // padding
+}
+
+// MetaSymbolHeader stores header information for a single
+// meta-data blob, e.g. the coverage meta-data payload
+// computed for a given Go package.
+type MetaSymbolHeader struct {
+	Length     uint32 // size of meta-symbol payload in bytes
+	PkgName    uint32 // string table index
+	PkgPath    uint32 // string table index
+	ModulePath uint32 // string table index
+	MetaHash   [16]byte
+	_          byte    // currently unused
+	_          [3]byte // padding
+	NumFiles   uint32
+	NumFuncs   uint32
+}
+
+const CovMetaHeaderSize = 16 + 4 + 4 + 4 + 4 + 4 + 4 + 4 // keep in sync with above
+
+// As an example, consider the following Go package:
+//
+// 01: package p
+// 02:
+// 03: var v, w, z int
+// 04:
+// 05: func small(x, y int) int {
+// 06:   v++
+// 07:   // comment
+// 08:   if y == 0 {
+// 09:     return x
+// 10:   }
+// 11:   return (x << 1) ^ (9 / y)
+// 12: }
+// 13:
+// 14: func Medium(q, r int) int {
+// 15:   s1 := small(q, r)
+// 16:   z += s1
+// 17:   s2 := small(r, q)
+// 18:   w -= s2
+// 19:   return w + z
+// 20: }
+//
+// The meta-data blob for the single package above might look like the
+// following:
+//
+// -- MetaSymbolHeader header----------
+//  | size: size of this blob in bytes
+//  | packagepath: <path to p>
+//  | modulepath: <modpath for p>
+//  | nfiles: 1
+//  | nfunctions: 2
+//  --func offsets table------
+//  <offset to func 0>
+//  <offset to func 1>
+//  --string table (contains all files and functions)------
+//  | <uleb128 len> 4
+//  | <data> "p.go"
+//  | <uleb128 len> 5
+//  | <data> "small"
+//  | <uleb128 len> 6
+//  | <data> "Medium"
+//  --func 0------
+//  | <uleb128> num units: 3
+//  | <uleb128> func name: S1 (index into string table)
+//  | <uleb128> file: S0 (index into string table)
+//  | <unit 0>:  S0   L6     L8    2
+//  | <unit 1>:  S0   L9     L9    1
+//  | <unit 2>:  S0   L11    L11   1
+//  --func 1------
+//  | <uleb128> num units: 1
+//  | <uleb128> func name: S2 (index into string table)
+//  | <uleb128> file: S0 (index into string table)
+//  | <unit 0>:  S0   L15    L19   5
+//  ---end-----------
+
+// The following types and constants used by the meta-data encoder/decoder.
+
+// FuncDesc encapsulates the meta-data definitions for a single Go function.
+// This version assumes that we're looking at a function before inlining;
+// if we want to capture a post-inlining view of the world, the
+// representations of source positions would need to be a good deal more
+// complicated.
+type FuncDesc struct {
+	Funcname string
+	Srcfile  string
+	Units    []CoverableUnit
+	Lit      bool // true if this is a function literal
+}
+
+// CoverableUnit describes the source characteristics of a single
+// program unit for which we want to gather coverage info. Coverable
+// units are either "simple" or "intraline"; a "simple" coverable unit
+// corresponds to a basic block (region of straight-line code with no
+// jumps or control transfers). An "intraline" unit corresponds to a
+// logical clause nested within some other simple unit. A simple unit
+// will have a zero Parent value; for an intraline unit NxStmts will
+// be zero and and Parent will be set to 1 plus the index of the
+// containing simple statement. Example:
+//
+//	L7:   q := 1
+//	L8:   x := (y == 101 || launch() == false)
+//	L9:   r := x * 2
+//
+// For the code above we would have three simple units (one for each
+// line), then an intraline unit describing the "launch() == false"
+// clause in line 8, with Parent pointing to the index of the line 8
+// unit in the units array.
+//
+// Note: in the initial version of the coverage revamp, only simple
+// units will be in use.
+type CoverableUnit struct {
+	StLine, StCol uint32
+	EnLine, EnCol uint32
+	NxStmts       uint32
+	Parent        uint32
+}
+
+// CounterMode tracks the "flavor" of the coverage counters being
+// used in a given coverage-instrumented program.
+type CounterMode uint8
+
+const (
+	CtrModeInvalid  CounterMode = iota
+	CtrModeSet                  // "set" mode
+	CtrModeCount                // "count" mode
+	CtrModeAtomic               // "atomic" mode
+	CtrModeRegOnly              // registration-only pseudo-mode
+	CtrModeTestMain             // testmain pseudo-mode
+)
+
+func (cm CounterMode) String() string {
+	switch cm {
+	case CtrModeSet:
+		return "set"
+	case CtrModeCount:
+		return "count"
+	case CtrModeAtomic:
+		return "atomic"
+	case CtrModeRegOnly:
+		return "regonly"
+	case CtrModeTestMain:
+		return "testmain"
+	}
+	return "<invalid>"
+}
+
+func ParseCounterMode(mode string) CounterMode {
+	var cm CounterMode
+	switch mode {
+	case "set":
+		cm = CtrModeSet
+	case "count":
+		cm = CtrModeCount
+	case "atomic":
+		cm = CtrModeAtomic
+	case "regonly":
+		cm = CtrModeRegOnly
+	case "testmain":
+		cm = CtrModeTestMain
+	default:
+		cm = CtrModeInvalid
+	}
+	return cm
+}
+
+// CounterGranularity tracks the granularity of the coverage counters being
+// used in a given coverage-instrumented program.
+type CounterGranularity uint8
+
+const (
+	CtrGranularityInvalid CounterGranularity = iota
+	CtrGranularityPerBlock
+	CtrGranularityPerFunc
+)
+
+func (cm CounterGranularity) String() string {
+	switch cm {
+	case CtrGranularityPerBlock:
+		return "perblock"
+	case CtrGranularityPerFunc:
+		return "perfunc"
+	}
+	return "<invalid>"
+}
+
+//.....................................................................
+//
+// Counter data definitions:
+//
+
+// A counter data file is composed of a file header followed by one or
+// more "segments" (each segment representing a given run or partial
+// run of a give binary) followed by a footer.
+
+// CovCounterMagic holds the magic string for a coverage counter-data file.
+var CovCounterMagic = [4]byte{'\x00', '\x63', '\x77', '\x6d'}
+
+// CounterFileVersion stores the most recent counter data file version.
+const CounterFileVersion = 1
+
+// CounterFileHeader stores files header information for a counter-data file.
+type CounterFileHeader struct {
+	Magic     [4]byte
+	Version   uint32
+	MetaHash  [16]byte
+	CFlavor   CounterFlavor
+	BigEndian bool
+	_         [6]byte // padding
+}
+
+// CounterSegmentHeader encapsulates information about a specific
+// segment in a counter data file, which at the moment contains
+// counters data from a single execution of a coverage-instrumented
+// program. Following the segment header will be the string table and
+// args table, and then (possibly) padding bytes to bring the byte
+// size of the preamble up to a multiple of 4. Immediately following
+// that will be the counter payloads.
+//
+// The "args" section of a segment is used to store annotations
+// describing where the counter data came from; this section is
+// basically a series of key-value pairs (can be thought of as an
+// encoded 'map[string]string'). At the moment we only write os.Args()
+// data to this section, using pairs of the form "argc=<integer>",
+// "argv0=<os.Args[0]>", "argv1=<os.Args[1]>", and so on. In the
+// future the args table may also include things like GOOS/GOARCH
+// values, and/or tags indicating which tests were run to generate the
+// counter data.
+type CounterSegmentHeader struct {
+	FcnEntries uint64
+	StrTabLen  uint32
+	ArgsLen    uint32
+}
+
+// CounterFileFooter appears at the tail end of a counter data file,
+// and stores the number of segments it contains.
+type CounterFileFooter struct {
+	Magic       [4]byte
+	_           [4]byte // padding
+	NumSegments uint32
+	_           [4]byte // padding
+}
+
+// CounterFilePref is the file prefix used when emitting coverage data
+// output files. CounterFileTemplate describes the format of the file
+// name: prefix followed by meta-file hash followed by process ID
+// followed by emit UnixNanoTime.
+const CounterFilePref = "covcounters"
+const CounterFileTempl = "%s.%x.%d.%d"
+const CounterFileRegexp = `^%s\.(\S+)\.(\d+)\.(\d+)+$`
+
+// CounterFlavor describes how function and counters are
+// stored/represented in the counter section of the file.
+type CounterFlavor uint8
+
+const (
+	// "Raw" representation: all values (pkg ID, func ID, num counters,
+	// and counters themselves) are stored as uint32's.
+	CtrRaw CounterFlavor = iota + 1
+
+	// "ULeb" representation: all values (pkg ID, func ID, num counters,
+	// and counters themselves) are stored with ULEB128 encoding.
+	CtrULeb128
+)
+
+func Round4(x int) int {
+	return (x + 3) &^ 3
+}
+
+//.....................................................................
+//
+// Runtime counter data definitions.
+//
+
+// At runtime within a coverage-instrumented program, the "counters"
+// object we associated with instrumented function can be thought of
+// as a struct of the following form:
+//
+// struct {
+//     numCtrs uint32
+//     pkgid uint32
+//     funcid uint32
+//     counterArray [numBlocks]uint32
+// }
+//
+// where "numCtrs" is the number of blocks / coverable units within the
+// function, "pkgid" is the unique index assigned to this package by
+// the runtime, "funcid" is the index of this function within its containing
+// package, and "counterArray" stores the actual counters.
+//
+// The counter variable itself is created not as a struct but as a flat
+// array of uint32's; we then use the offsets below to index into it.
+
+const NumCtrsOffset = 0
+const PkgIdOffset = 1
+const FuncIdOffset = 2
+const FirstCtrOffset = 3
diff --git a/contrib/go/_std_1.20/src/internal/coverage/encodecounter/encode.go b/contrib/go/_std_1.20/src/internal/coverage/encodecounter/encode.go
new file mode 100644
index 0000000000..8db4f514e8
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/encodecounter/encode.go
@@ -0,0 +1,284 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package encodecounter
+
+import (
+	"bufio"
+	"encoding/binary"
+	"fmt"
+	"internal/coverage"
+	"internal/coverage/slicewriter"
+	"internal/coverage/stringtab"
+	"internal/coverage/uleb128"
+	"io"
+	"os"
+	"sort"
+)
+
+// This package contains APIs and helpers for encoding initial portions
+// of the counter data files emitted at runtime when coverage instrumentation
+// is enabled.  Counter data files may contain multiple segments; the file
+// header and first segment are written via the "Write" method below, and
+// additional segments can then be added using "AddSegment".
+
+type CoverageDataWriter struct {
+	stab    *stringtab.Writer
+	w       *bufio.Writer
+	tmp     []byte
+	cflavor coverage.CounterFlavor
+	segs    uint32
+	debug   bool
+}
+
+func NewCoverageDataWriter(w io.Writer, flav coverage.CounterFlavor) *CoverageDataWriter {
+	r := &CoverageDataWriter{
+		stab: &stringtab.Writer{},
+		w:    bufio.NewWriter(w),
+
+		tmp:     make([]byte, 64),
+		cflavor: flav,
+	}
+	r.stab.InitWriter()
+	r.stab.Lookup("")
+	return r
+}
+
+// CounterVisitor describes a helper object used during counter file
+// writing; when writing counter data files, clients pass a
+// CounterVisitor to the write/emit routines. The writers will then
+// first invoke the visitor's NumFuncs() method to find out how many
+// function's worth of data to write, then it will invoke VisitFuncs.
+// The expectation is that the VisitFuncs method will then invoke the
+// callback "f" with data for each function to emit to the file.
+type CounterVisitor interface {
+	NumFuncs() (int, error)
+	VisitFuncs(f CounterVisitorFn) error
+}
+
+// CounterVisitorFn describes a callback function invoked when writing
+// coverage counter data.
+type CounterVisitorFn func(pkid uint32, funcid uint32, counters []uint32) error
+
+// Write writes the contents of the count-data file to the writer
+// previously supplied to NewCoverageDataWriter. Returns an error
+// if something went wrong somewhere with the write.
+func (cfw *CoverageDataWriter) Write(metaFileHash [16]byte, args map[string]string, visitor CounterVisitor) error {
+	if err := cfw.writeHeader(metaFileHash); err != nil {
+		return err
+	}
+	return cfw.AppendSegment(args, visitor)
+}
+
+func padToFourByteBoundary(ws *slicewriter.WriteSeeker) error {
+	sz := len(ws.BytesWritten())
+	zeros := []byte{0, 0, 0, 0}
+	rem := uint32(sz) % 4
+	if rem != 0 {
+		pad := zeros[:(4 - rem)]
+		if nw, err := ws.Write(pad); err != nil {
+			return err
+		} else if nw != len(pad) {
+			return fmt.Errorf("error: short write")
+		}
+	}
+	return nil
+}
+
+func (cfw *CoverageDataWriter) writeSegmentPreamble(args map[string]string, visitor CounterVisitor) error {
+	var csh coverage.CounterSegmentHeader
+	if nf, err := visitor.NumFuncs(); err != nil {
+		return err
+	} else {
+		csh.FcnEntries = uint64(nf)
+	}
+
+	// Write string table and args to a byte slice (since we need
+	// to capture offsets at various points), then emit the slice
+	// once we are done.
+	cfw.stab.Freeze()
+	ws := &slicewriter.WriteSeeker{}
+	if err := cfw.stab.Write(ws); err != nil {
+		return err
+	}
+	csh.StrTabLen = uint32(len(ws.BytesWritten()))
+
+	akeys := make([]string, 0, len(args))
+	for k := range args {
+		akeys = append(akeys, k)
+	}
+	sort.Strings(akeys)
+
+	wrULEB128 := func(v uint) error {
+		cfw.tmp = cfw.tmp[:0]
+		cfw.tmp = uleb128.AppendUleb128(cfw.tmp, v)
+		if _, err := ws.Write(cfw.tmp); err != nil {
+			return err
+		}
+		return nil
+	}
+
+	// Count of arg pairs.
+	if err := wrULEB128(uint(len(args))); err != nil {
+		return err
+	}
+	// Arg pairs themselves.
+	for _, k := range akeys {
+		ki := uint(cfw.stab.Lookup(k))
+		if err := wrULEB128(ki); err != nil {
+			return err
+		}
+		v := args[k]
+		vi := uint(cfw.stab.Lookup(v))
+		if err := wrULEB128(vi); err != nil {
+			return err
+		}
+	}
+	if err := padToFourByteBoundary(ws); err != nil {
+		return err
+	}
+	csh.ArgsLen = uint32(len(ws.BytesWritten())) - csh.StrTabLen
+
+	if cfw.debug {
+		fmt.Fprintf(os.Stderr, "=-= counter segment header: %+v", csh)
+		fmt.Fprintf(os.Stderr, " FcnEntries=0x%x StrTabLen=0x%x ArgsLen=0x%x\n",
+			csh.FcnEntries, csh.StrTabLen, csh.ArgsLen)
+	}
+
+	// At this point we can now do the actual write.
+	if err := binary.Write(cfw.w, binary.LittleEndian, csh); err != nil {
+		return err
+	}
+	if err := cfw.writeBytes(ws.BytesWritten()); err != nil {
+		return err
+	}
+	return nil
+}
+
+// AppendSegment appends a new segment to a counter data, with a new
+// args section followed by a payload of counter data clauses.
+func (cfw *CoverageDataWriter) AppendSegment(args map[string]string, visitor CounterVisitor) error {
+	cfw.stab = &stringtab.Writer{}
+	cfw.stab.InitWriter()
+	cfw.stab.Lookup("")
+
+	var err error
+	for k, v := range args {
+		cfw.stab.Lookup(k)
+		cfw.stab.Lookup(v)
+	}
+
+	if err = cfw.writeSegmentPreamble(args, visitor); err != nil {
+		return err
+	}
+	if err = cfw.writeCounters(visitor); err != nil {
+		return err
+	}
+	if err = cfw.writeFooter(); err != nil {
+		return err
+	}
+	if err := cfw.w.Flush(); err != nil {
+		return fmt.Errorf("write error: %v", err)
+	}
+	cfw.stab = nil
+	return nil
+}
+
+func (cfw *CoverageDataWriter) writeHeader(metaFileHash [16]byte) error {
+	// Emit file header.
+	ch := coverage.CounterFileHeader{
+		Magic:     coverage.CovCounterMagic,
+		Version:   coverage.CounterFileVersion,
+		MetaHash:  metaFileHash,
+		CFlavor:   cfw.cflavor,
+		BigEndian: false,
+	}
+	if err := binary.Write(cfw.w, binary.LittleEndian, ch); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (cfw *CoverageDataWriter) writeBytes(b []byte) error {
+	if len(b) == 0 {
+		return nil
+	}
+	nw, err := cfw.w.Write(b)
+	if err != nil {
+		return fmt.Errorf("error writing counter data: %v", err)
+	}
+	if len(b) != nw {
+		return fmt.Errorf("error writing counter data: short write")
+	}
+	return nil
+}
+
+func (cfw *CoverageDataWriter) writeCounters(visitor CounterVisitor) error {
+	// Notes:
+	// - this version writes everything little-endian, which means
+	//   a call is needed to encode every value (expensive)
+	// - we may want to move to a model in which we just blast out
+	//   all counters, or possibly mmap the file and do the write
+	//   implicitly.
+	ctrb := make([]byte, 4)
+	wrval := func(val uint32) error {
+		var buf []byte
+		var towr int
+		if cfw.cflavor == coverage.CtrRaw {
+			binary.LittleEndian.PutUint32(ctrb, val)
+			buf = ctrb
+			towr = 4
+		} else if cfw.cflavor == coverage.CtrULeb128 {
+			cfw.tmp = cfw.tmp[:0]
+			cfw.tmp = uleb128.AppendUleb128(cfw.tmp, uint(val))
+			buf = cfw.tmp
+			towr = len(buf)
+		} else {
+			panic("internal error: bad counter flavor")
+		}
+		if sz, err := cfw.w.Write(buf); err != nil {
+			return err
+		} else if sz != towr {
+			return fmt.Errorf("writing counters: short write")
+		}
+		return nil
+	}
+
+	// Write out entries for each live function.
+	emitter := func(pkid uint32, funcid uint32, counters []uint32) error {
+		if err := wrval(uint32(len(counters))); err != nil {
+			return err
+		}
+
+		if err := wrval(pkid); err != nil {
+			return err
+		}
+
+		if err := wrval(funcid); err != nil {
+			return err
+		}
+		for _, val := range counters {
+			if err := wrval(val); err != nil {
+				return err
+			}
+		}
+		return nil
+	}
+	if err := visitor.VisitFuncs(emitter); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (cfw *CoverageDataWriter) writeFooter() error {
+	cfw.segs++
+	cf := coverage.CounterFileFooter{
+		Magic:       coverage.CovCounterMagic,
+		NumSegments: cfw.segs,
+	}
+	if err := binary.Write(cfw.w, binary.LittleEndian, cf); err != nil {
+		return err
+	}
+	return nil
+}
diff --git a/contrib/go/_std_1.20/src/internal/coverage/encodecounter/ya.make b/contrib/go/_std_1.20/src/internal/coverage/encodecounter/ya.make
new file mode 100644
index 0000000000..fb82cc2fd2
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/encodecounter/ya.make
@@ -0,0 +1,7 @@
+GO_LIBRARY()
+
+SRCS(
+    encode.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/coverage/encodemeta/encode.go b/contrib/go/_std_1.20/src/internal/coverage/encodemeta/encode.go
new file mode 100644
index 0000000000..d211c7c08e
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/encodemeta/encode.go
@@ -0,0 +1,215 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package encodemeta
+
+// This package contains APIs and helpers for encoding the meta-data
+// "blob" for a single Go package, created when coverage
+// instrumentation is turned on.
+
+import (
+	"bytes"
+	"crypto/md5"
+	"encoding/binary"
+	"fmt"
+	"hash"
+	"internal/coverage"
+	"internal/coverage/stringtab"
+	"internal/coverage/uleb128"
+	"io"
+	"os"
+)
+
+type CoverageMetaDataBuilder struct {
+	stab    stringtab.Writer
+	funcs   []funcDesc
+	tmp     []byte // temp work slice
+	h       hash.Hash
+	pkgpath uint32
+	pkgname uint32
+	modpath uint32
+	debug   bool
+	werr    error
+}
+
+func NewCoverageMetaDataBuilder(pkgpath string, pkgname string, modulepath string) (*CoverageMetaDataBuilder, error) {
+	if pkgpath == "" {
+		return nil, fmt.Errorf("invalid empty package path")
+	}
+	x := &CoverageMetaDataBuilder{
+		tmp: make([]byte, 0, 256),
+		h:   md5.New(),
+	}
+	x.stab.InitWriter()
+	x.stab.Lookup("")
+	x.pkgpath = x.stab.Lookup(pkgpath)
+	x.pkgname = x.stab.Lookup(pkgname)
+	x.modpath = x.stab.Lookup(modulepath)
+	io.WriteString(x.h, pkgpath)
+	io.WriteString(x.h, pkgname)
+	io.WriteString(x.h, modulepath)
+	return x, nil
+}
+
+func h32(x uint32, h hash.Hash, tmp []byte) {
+	tmp = tmp[:0]
+	tmp = append(tmp, []byte{0, 0, 0, 0}...)
+	binary.LittleEndian.PutUint32(tmp, x)
+	h.Write(tmp)
+}
+
+type funcDesc struct {
+	encoded []byte
+}
+
+// AddFunc registers a new function with the meta data builder.
+func (b *CoverageMetaDataBuilder) AddFunc(f coverage.FuncDesc) uint {
+	hashFuncDesc(b.h, &f, b.tmp)
+	fd := funcDesc{}
+	b.tmp = b.tmp[:0]
+	b.tmp = uleb128.AppendUleb128(b.tmp, uint(len(f.Units)))
+	b.tmp = uleb128.AppendUleb128(b.tmp, uint(b.stab.Lookup(f.Funcname)))
+	b.tmp = uleb128.AppendUleb128(b.tmp, uint(b.stab.Lookup(f.Srcfile)))
+	for _, u := range f.Units {
+		b.tmp = uleb128.AppendUleb128(b.tmp, uint(u.StLine))
+		b.tmp = uleb128.AppendUleb128(b.tmp, uint(u.StCol))
+		b.tmp = uleb128.AppendUleb128(b.tmp, uint(u.EnLine))
+		b.tmp = uleb128.AppendUleb128(b.tmp, uint(u.EnCol))
+		b.tmp = uleb128.AppendUleb128(b.tmp, uint(u.NxStmts))
+	}
+	lit := uint(0)
+	if f.Lit {
+		lit = 1
+	}
+	b.tmp = uleb128.AppendUleb128(b.tmp, lit)
+	fd.encoded = bytes.Clone(b.tmp)
+	rv := uint(len(b.funcs))
+	b.funcs = append(b.funcs, fd)
+	return rv
+}
+
+func (b *CoverageMetaDataBuilder) emitFuncOffsets(w io.WriteSeeker, off int64) int64 {
+	nFuncs := len(b.funcs)
+	var foff int64 = coverage.CovMetaHeaderSize + int64(b.stab.Size()) + int64(nFuncs)*4
+	for idx := 0; idx < nFuncs; idx++ {
+		b.wrUint32(w, uint32(foff))
+		foff += int64(len(b.funcs[idx].encoded))
+	}
+	return off + (int64(len(b.funcs)) * 4)
+}
+
+func (b *CoverageMetaDataBuilder) emitFunc(w io.WriteSeeker, off int64, f funcDesc) (int64, error) {
+	ew := len(f.encoded)
+	if nw, err := w.Write(f.encoded); err != nil {
+		return 0, err
+	} else if ew != nw {
+		return 0, fmt.Errorf("short write emitting coverage meta-data")
+	}
+	return off + int64(ew), nil
+}
+
+func (b *CoverageMetaDataBuilder) reportWriteError(err error) {
+	if b.werr != nil {
+		b.werr = err
+	}
+}
+
+func (b *CoverageMetaDataBuilder) wrUint32(w io.WriteSeeker, v uint32) {
+	b.tmp = b.tmp[:0]
+	b.tmp = append(b.tmp, []byte{0, 0, 0, 0}...)
+	binary.LittleEndian.PutUint32(b.tmp, v)
+	if nw, err := w.Write(b.tmp); err != nil {
+		b.reportWriteError(err)
+	} else if nw != 4 {
+		b.reportWriteError(fmt.Errorf("short write"))
+	}
+}
+
+// Emit writes the meta-data accumulated so far in this builder to 'w'.
+// Returns a hash of the meta-data payload and an error.
+func (b *CoverageMetaDataBuilder) Emit(w io.WriteSeeker) ([16]byte, error) {
+	// Emit header.  Length will initially be zero, we'll
+	// back-patch it later.
+	var digest [16]byte
+	copy(digest[:], b.h.Sum(nil))
+	mh := coverage.MetaSymbolHeader{
+		// hash and length initially zero, will be back-patched
+		PkgPath:    uint32(b.pkgpath),
+		PkgName:    uint32(b.pkgname),
+		ModulePath: uint32(b.modpath),
+		NumFiles:   uint32(b.stab.Nentries()),
+		NumFuncs:   uint32(len(b.funcs)),
+		MetaHash:   digest,
+	}
+	if b.debug {
+		fmt.Fprintf(os.Stderr, "=-= writing header: %+v\n", mh)
+	}
+	if err := binary.Write(w, binary.LittleEndian, mh); err != nil {
+		return digest, fmt.Errorf("error writing meta-file header: %v", err)
+	}
+	off := int64(coverage.CovMetaHeaderSize)
+
+	// Write function offsets section
+	off = b.emitFuncOffsets(w, off)
+
+	// Check for any errors up to this point.
+	if b.werr != nil {
+		return digest, b.werr
+	}
+
+	// Write string table.
+	if err := b.stab.Write(w); err != nil {
+		return digest, err
+	}
+	off += int64(b.stab.Size())
+
+	// Write functions
+	for _, f := range b.funcs {
+		var err error
+		off, err = b.emitFunc(w, off, f)
+		if err != nil {
+			return digest, err
+		}
+	}
+
+	// Back-patch the length.
+	totalLength := uint32(off)
+	if _, err := w.Seek(0, io.SeekStart); err != nil {
+		return digest, err
+	}
+	b.wrUint32(w, totalLength)
+	if b.werr != nil {
+		return digest, b.werr
+	}
+	return digest, nil
+}
+
+// HashFuncDesc computes an md5 sum of a coverage.FuncDesc and returns
+// a digest for it.
+func HashFuncDesc(f *coverage.FuncDesc) [16]byte {
+	h := md5.New()
+	tmp := make([]byte, 0, 32)
+	hashFuncDesc(h, f, tmp)
+	var r [16]byte
+	copy(r[:], h.Sum(nil))
+	return r
+}
+
+// hashFuncDesc incorporates a given function 'f' into the hash 'h'.
+func hashFuncDesc(h hash.Hash, f *coverage.FuncDesc, tmp []byte) {
+	io.WriteString(h, f.Funcname)
+	io.WriteString(h, f.Srcfile)
+	for _, u := range f.Units {
+		h32(u.StLine, h, tmp)
+		h32(u.StCol, h, tmp)
+		h32(u.EnLine, h, tmp)
+		h32(u.EnCol, h, tmp)
+		h32(u.NxStmts, h, tmp)
+	}
+	lit := uint32(0)
+	if f.Lit {
+		lit = 1
+	}
+	h32(lit, h, tmp)
+}
diff --git a/contrib/go/_std_1.20/src/internal/coverage/encodemeta/encodefile.go b/contrib/go/_std_1.20/src/internal/coverage/encodemeta/encodefile.go
new file mode 100644
index 0000000000..38ae46e4f5
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/encodemeta/encodefile.go
@@ -0,0 +1,132 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package encodemeta
+
+import (
+	"bufio"
+	"crypto/md5"
+	"encoding/binary"
+	"fmt"
+	"internal/coverage"
+	"internal/coverage/stringtab"
+	"io"
+	"os"
+	"unsafe"
+)
+
+// This package contains APIs and helpers for writing out a meta-data
+// file (composed of a file header, offsets/lengths, and then a series of
+// meta-data blobs emitted by the compiler, one per Go package).
+
+type CoverageMetaFileWriter struct {
+	stab   stringtab.Writer
+	mfname string
+	w      *bufio.Writer
+	tmp    []byte
+	debug  bool
+}
+
+func NewCoverageMetaFileWriter(mfname string, w io.Writer) *CoverageMetaFileWriter {
+	r := &CoverageMetaFileWriter{
+		mfname: mfname,
+		w:      bufio.NewWriter(w),
+		tmp:    make([]byte, 64),
+	}
+	r.stab.InitWriter()
+	r.stab.Lookup("")
+	return r
+}
+
+func (m *CoverageMetaFileWriter) Write(finalHash [16]byte, blobs [][]byte, mode coverage.CounterMode, granularity coverage.CounterGranularity) error {
+	mhsz := uint64(unsafe.Sizeof(coverage.MetaFileHeader{}))
+	stSize := m.stab.Size()
+	stOffset := mhsz + uint64(16*len(blobs))
+	preambleLength := stOffset + uint64(stSize)
+
+	if m.debug {
+		fmt.Fprintf(os.Stderr, "=+= sizeof(MetaFileHeader)=%d\n", mhsz)
+		fmt.Fprintf(os.Stderr, "=+= preambleLength=%d stSize=%d\n", preambleLength, stSize)
+	}
+
+	// Compute total size
+	tlen := preambleLength
+	for i := 0; i < len(blobs); i++ {
+		tlen += uint64(len(blobs[i]))
+	}
+
+	// Emit header
+	mh := coverage.MetaFileHeader{
+		Magic:        coverage.CovMetaMagic,
+		Version:      coverage.MetaFileVersion,
+		TotalLength:  tlen,
+		Entries:      uint64(len(blobs)),
+		MetaFileHash: finalHash,
+		StrTabOffset: uint32(stOffset),
+		StrTabLength: stSize,
+		CMode:        mode,
+		CGranularity: granularity,
+	}
+	var err error
+	if err = binary.Write(m.w, binary.LittleEndian, mh); err != nil {
+		return fmt.Errorf("error writing %s: %v", m.mfname, err)
+	}
+
+	if m.debug {
+		fmt.Fprintf(os.Stderr, "=+= len(blobs) is %d\n", mh.Entries)
+	}
+
+	// Emit package offsets section followed by package lengths section.
+	off := preambleLength
+	off2 := mhsz
+	buf := make([]byte, 8)
+	for _, blob := range blobs {
+		binary.LittleEndian.PutUint64(buf, off)
+		if _, err = m.w.Write(buf); err != nil {
+			return fmt.Errorf("error writing %s: %v", m.mfname, err)
+		}
+		if m.debug {
+			fmt.Fprintf(os.Stderr, "=+= pkg offset %d 0x%x\n", off, off)
+		}
+		off += uint64(len(blob))
+		off2 += 8
+	}
+	for _, blob := range blobs {
+		bl := uint64(len(blob))
+		binary.LittleEndian.PutUint64(buf, bl)
+		if _, err = m.w.Write(buf); err != nil {
+			return fmt.Errorf("error writing %s: %v", m.mfname, err)
+		}
+		if m.debug {
+			fmt.Fprintf(os.Stderr, "=+= pkg len %d 0x%x\n", bl, bl)
+		}
+		off2 += 8
+	}
+
+	// Emit string table
+	if err = m.stab.Write(m.w); err != nil {
+		return err
+	}
+
+	// Now emit blobs themselves.
+	for k, blob := range blobs {
+		if m.debug {
+			fmt.Fprintf(os.Stderr, "=+= writing blob %d len %d at off=%d hash %s\n", k, len(blob), off2, fmt.Sprintf("%x", md5.Sum(blob)))
+		}
+		if _, err = m.w.Write(blob); err != nil {
+			return fmt.Errorf("error writing %s: %v", m.mfname, err)
+		}
+		if m.debug {
+			fmt.Fprintf(os.Stderr, "=+= wrote package payload of %d bytes\n",
+				len(blob))
+		}
+		off2 += uint64(len(blob))
+	}
+
+	// Flush writer, and we're done.
+	if err = m.w.Flush(); err != nil {
+		return fmt.Errorf("error writing %s: %v", m.mfname, err)
+	}
+	return nil
+}
diff --git a/contrib/go/_std_1.20/src/internal/coverage/encodemeta/ya.make b/contrib/go/_std_1.20/src/internal/coverage/encodemeta/ya.make
new file mode 100644
index 0000000000..ecc0df9460
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/encodemeta/ya.make
@@ -0,0 +1,8 @@
+GO_LIBRARY()
+
+SRCS(
+    encode.go
+    encodefile.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/coverage/pkid.go b/contrib/go/_std_1.20/src/internal/coverage/pkid.go
new file mode 100644
index 0000000000..8ddd44d6bb
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/pkid.go
@@ -0,0 +1,80 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package coverage
+
+// Building the runtime package with coverage instrumentation enabled
+// is tricky.  For all other packages, you can be guaranteed that
+// the package init function is run before any functions are executed,
+// but this invariant is not maintained for packages such as "runtime",
+// "internal/cpu", etc. To handle this, hard-code the package ID for
+// the set of packages whose functions may be running before the
+// init function of the package is complete.
+//
+// Hardcoding is unfortunate because it means that the tool that does
+// coverage instrumentation has to keep a list of runtime packages,
+// meaning that if someone makes changes to the pkg "runtime"
+// dependencies, unexpected behavior will result for coverage builds.
+// The coverage runtime will detect and report the unexpected
+// behavior; look for an error of this form:
+//
+//    internal error in coverage meta-data tracking:
+//    list of hard-coded runtime package IDs needs revising.
+//    registered list:
+//    slot: 0 path='internal/cpu'  hard-coded id: 1
+//    slot: 1 path='internal/goarch'  hard-coded id: 2
+//    slot: 2 path='runtime/internal/atomic'  hard-coded id: 3
+//    slot: 3 path='internal/goos'
+//    slot: 4 path='runtime/internal/sys'  hard-coded id: 5
+//    slot: 5 path='internal/abi'  hard-coded id: 4
+//    slot: 6 path='runtime/internal/math'  hard-coded id: 6
+//    slot: 7 path='internal/bytealg'  hard-coded id: 7
+//    slot: 8 path='internal/goexperiment'
+//    slot: 9 path='runtime/internal/syscall'  hard-coded id: 8
+//    slot: 10 path='runtime'  hard-coded id: 9
+//    fatal error: runtime.addCovMeta
+//
+// For the error above, the hard-coded list is missing "internal/goos"
+// and "internal/goexperiment" ; the developer in question will need
+// to copy the list above into "rtPkgs" below.
+//
+// Note: this strategy assumes that the list of dependencies of
+// package runtime is fixed, and doesn't vary depending on OS/arch. If
+// this were to be the case, we would need a table of some sort below
+// as opposed to a fixed list.
+
+var rtPkgs = [...]string{
+	"internal/cpu",
+	"internal/goarch",
+	"runtime/internal/atomic",
+	"internal/goos",
+	"runtime/internal/sys",
+	"internal/abi",
+	"runtime/internal/math",
+	"internal/bytealg",
+	"internal/goexperiment",
+	"runtime/internal/syscall",
+	"runtime",
+}
+
+// Scoping note: the constants and apis in this file are internal
+// only, not expected to ever be exposed outside of the runtime (unlike
+// other coverage file formats and APIs, which will likely be shared
+// at some point).
+
+// NotHardCoded is a package pseudo-ID indicating that a given package
+// is not part of the runtime and doesn't require a hard-coded ID.
+const NotHardCoded = -1
+
+// HardCodedPkgID returns the hard-coded ID for the specified package
+// path, or -1 if we don't use a hard-coded ID. Hard-coded IDs start
+// at -2 and decrease as we go down the list.
+func HardCodedPkgID(pkgpath string) int {
+	for k, p := range rtPkgs {
+		if p == pkgpath {
+			return (0 - k) - 2
+		}
+	}
+	return NotHardCoded
+}
diff --git a/contrib/go/_std_1.20/src/internal/coverage/pods/pods.go b/contrib/go/_std_1.20/src/internal/coverage/pods/pods.go
new file mode 100644
index 0000000000..432c7b6bd6
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/pods/pods.go
@@ -0,0 +1,194 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package pods
+
+import (
+	"fmt"
+	"internal/coverage"
+	"os"
+	"path/filepath"
+	"regexp"
+	"sort"
+	"strconv"
+)
+
+// Pod encapsulates a set of files emitted during the executions of a
+// coverage-instrumented binary. Each pod contains a single meta-data
+// file, and then 0 or more counter data files that refer to that
+// meta-data file. Pods are intended to simplify processing of
+// coverage output files in the case where we have several coverage
+// output directories containing output files derived from more
+// than one instrumented executable. In the case where the files that
+// make up a pod are spread out across multiple directories, each
+// element of the "Origins" field below will be populated with the
+// index of the originating directory for the corresponding counter
+// data file (within the slice of input dirs handed to CollectPods).
+// The ProcessIDs field will be populated with the process ID of each
+// data file in the CounterDataFiles slice.
+type Pod struct {
+	MetaFile         string
+	CounterDataFiles []string
+	Origins          []int
+	ProcessIDs       []int
+}
+
+// CollectPods visits the files contained within the directories in
+// the list 'dirs', collects any coverage-related files, partitions
+// them into pods, and returns a list of the pods to the caller, along
+// with an error if something went wrong during directory/file
+// reading.
+//
+// CollectPods skips over any file that is not related to coverage
+// (e.g. avoids looking at things that are not meta-data files or
+// counter-data files). CollectPods also skips over 'orphaned' counter
+// data files (e.g. counter data files for which we can't find the
+// corresponding meta-data file). If "warn" is true, CollectPods will
+// issue warnings to stderr when it encounters non-fatal problems (for
+// orphans or a directory with no meta-data files).
+func CollectPods(dirs []string, warn bool) ([]Pod, error) {
+	files := []string{}
+	dirIndices := []int{}
+	for k, dir := range dirs {
+		dents, err := os.ReadDir(dir)
+		if err != nil {
+			return nil, err
+		}
+		for _, e := range dents {
+			if e.IsDir() {
+				continue
+			}
+			files = append(files, filepath.Join(dir, e.Name()))
+			dirIndices = append(dirIndices, k)
+		}
+	}
+	return collectPodsImpl(files, dirIndices, warn), nil
+}
+
+// CollectPodsFromFiles functions the same as "CollectPods" but
+// operates on an explicit list of files instead of a directory.
+func CollectPodsFromFiles(files []string, warn bool) []Pod {
+	return collectPodsImpl(files, nil, warn)
+}
+
+type fileWithAnnotations struct {
+	file   string
+	origin int
+	pid    int
+}
+
+type protoPod struct {
+	mf       string
+	elements []fileWithAnnotations
+}
+
+// collectPodsImpl examines the specified list of files and picks out
+// subsets that correspond to coverage pods. The first stage in this
+// process is collecting a set { M1, M2, ... MN } where each M_k is a
+// distinct coverage meta-data file. We then create a single pod for
+// each meta-data file M_k, then find all of the counter data files
+// that refer to that meta-data file (recall that the counter data
+// file name incorporates the meta-data hash), and add the counter
+// data file to the appropriate pod.
+//
+// This process is complicated by the fact that we need to keep track
+// of directory indices for counter data files. Here is an example to
+// motivate:
+//
+//	directory 1:
+//
+// M1   covmeta.9bbf1777f47b3fcacb05c38b035512d6
+// C1   covcounters.9bbf1777f47b3fcacb05c38b035512d6.1677673.1662138360208416486
+// C2   covcounters.9bbf1777f47b3fcacb05c38b035512d6.1677637.1662138359974441782
+//
+//	directory 2:
+//
+// M2   covmeta.9bbf1777f47b3fcacb05c38b035512d6
+// C3   covcounters.9bbf1777f47b3fcacb05c38b035512d6.1677445.1662138360208416480
+// C4   covcounters.9bbf1777f47b3fcacb05c38b035512d6.1677677.1662138359974441781
+// M3   covmeta.a723844208cea2ae80c63482c78b2245
+// C5   covcounters.a723844208cea2ae80c63482c78b2245.3677445.1662138360208416480
+// C6   covcounters.a723844208cea2ae80c63482c78b2245.1877677.1662138359974441781
+//
+// In these two directories we have three meta-data files, but only
+// two are distinct, meaning that we'll wind up with two pods. The
+// first pod (with meta-file M1) will have four counter data files
+// (C1, C2, C3, C4) and the second pod will have two counter data files
+// (C5, C6).
+func collectPodsImpl(files []string, dirIndices []int, warn bool) []Pod {
+	metaRE := regexp.MustCompile(fmt.Sprintf(`^%s\.(\S+)$`, coverage.MetaFilePref))
+	mm := make(map[string]protoPod)
+	for _, f := range files {
+		base := filepath.Base(f)
+		if m := metaRE.FindStringSubmatch(base); m != nil {
+			tag := m[1]
+			// We need to allow for the possibility of duplicate
+			// meta-data files. If we hit this case, use the
+			// first encountered as the canonical version.
+			if _, ok := mm[tag]; !ok {
+				mm[tag] = protoPod{mf: f}
+			}
+			// FIXME: should probably check file length and hash here for
+			// the duplicate.
+		}
+	}
+	counterRE := regexp.MustCompile(fmt.Sprintf(coverage.CounterFileRegexp, coverage.CounterFilePref))
+	for k, f := range files {
+		base := filepath.Base(f)
+		if m := counterRE.FindStringSubmatch(base); m != nil {
+			tag := m[1] // meta hash
+			pid, err := strconv.Atoi(m[2])
+			if err != nil {
+				continue
+			}
+			if v, ok := mm[tag]; ok {
+				idx := -1
+				if dirIndices != nil {
+					idx = dirIndices[k]
+				}
+				fo := fileWithAnnotations{file: f, origin: idx, pid: pid}
+				v.elements = append(v.elements, fo)
+				mm[tag] = v
+			} else {
+				if warn {
+					warning("skipping orphaned counter file: %s", f)
+				}
+			}
+		}
+	}
+	if len(mm) == 0 {
+		if warn {
+			warning("no coverage data files found")
+		}
+		return nil
+	}
+	pods := make([]Pod, 0, len(mm))
+	for _, p := range mm {
+		sort.Slice(p.elements, func(i, j int) bool {
+			return p.elements[i].file < p.elements[j].file
+		})
+		pod := Pod{
+			MetaFile:         p.mf,
+			CounterDataFiles: make([]string, 0, len(p.elements)),
+			Origins:          make([]int, 0, len(p.elements)),
+			ProcessIDs:       make([]int, 0, len(p.elements)),
+		}
+		for _, e := range p.elements {
+			pod.CounterDataFiles = append(pod.CounterDataFiles, e.file)
+			pod.Origins = append(pod.Origins, e.origin)
+			pod.ProcessIDs = append(pod.ProcessIDs, e.pid)
+		}
+		pods = append(pods, pod)
+	}
+	sort.Slice(pods, func(i, j int) bool {
+		return pods[i].MetaFile < pods[j].MetaFile
+	})
+	return pods
+}
+
+func warning(s string, a ...interface{}) {
+	fmt.Fprintf(os.Stderr, "warning: ")
+	fmt.Fprintf(os.Stderr, s, a...)
+	fmt.Fprintf(os.Stderr, "\n")
+}
diff --git a/contrib/go/_std_1.20/src/internal/coverage/pods/ya.make b/contrib/go/_std_1.20/src/internal/coverage/pods/ya.make
new file mode 100644
index 0000000000..2a226abc34
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/pods/ya.make
@@ -0,0 +1,7 @@
+GO_LIBRARY()
+
+SRCS(
+    pods.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/coverage/rtcov/rtcov.go b/contrib/go/_std_1.20/src/internal/coverage/rtcov/rtcov.go
new file mode 100644
index 0000000000..bbb93acced
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/rtcov/rtcov.go
@@ -0,0 +1,34 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package rtcov
+
+// This package contains types whose structure is shared between
+// the runtime package and the "runtime/coverage" package.
+
+// CovMetaBlob is a container for holding the meta-data symbol (an
+// RODATA variable) for an instrumented Go package. Here "p" points to
+// the symbol itself, "len" is the length of the sym in bytes, and
+// "hash" is an md5sum for the sym computed by the compiler. When
+// the init function for a coverage-instrumented package executes, it
+// will make a call into the runtime which will create a covMetaBlob
+// object for the package and chain it onto a global list.
+type CovMetaBlob struct {
+	P                  *byte
+	Len                uint32
+	Hash               [16]byte
+	PkgPath            string
+	PkgID              int
+	CounterMode        uint8 // coverage.CounterMode
+	CounterGranularity uint8 // coverage.CounterGranularity
+}
+
+// CovCounterBlob is a container for encapsulating a counter section
+// (BSS variable) for an instrumented Go module. Here "counters"
+// points to the counter payload and "len" is the number of uint32
+// entries in the section.
+type CovCounterBlob struct {
+	Counters *uint32
+	Len      uint64
+}
diff --git a/contrib/go/_std_1.20/src/internal/coverage/rtcov/ya.make b/contrib/go/_std_1.20/src/internal/coverage/rtcov/ya.make
new file mode 100644
index 0000000000..b686d3174e
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/rtcov/ya.make
@@ -0,0 +1,7 @@
+GO_LIBRARY()
+
+SRCS(
+    rtcov.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/coverage/slicereader/slicereader.go b/contrib/go/_std_1.20/src/internal/coverage/slicereader/slicereader.go
new file mode 100644
index 0000000000..3d117bae37
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/slicereader/slicereader.go
@@ -0,0 +1,98 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package slicereader
+
+import (
+	"encoding/binary"
+	"unsafe"
+)
+
+// This file contains the helper "SliceReader", a utility for
+// reading values from a byte slice that may or may not be backed
+// by a read-only mmap'd region.
+
+type Reader struct {
+	b        []byte
+	readonly bool
+	off      int64
+}
+
+func NewReader(b []byte, readonly bool) *Reader {
+	r := Reader{
+		b:        b,
+		readonly: readonly,
+	}
+	return &r
+}
+
+func (r *Reader) Read(b []byte) (int, error) {
+	amt := len(b)
+	toread := r.b[r.off:]
+	if len(toread) < amt {
+		amt = len(toread)
+	}
+	copy(b, toread)
+	r.off += int64(amt)
+	return amt, nil
+}
+
+func (r *Reader) SeekTo(off int64) {
+	r.off = off
+}
+
+func (r *Reader) Offset() int64 {
+	return r.off
+}
+
+func (r *Reader) ReadUint8() uint8 {
+	rv := uint8(r.b[int(r.off)])
+	r.off += 1
+	return rv
+}
+
+func (r *Reader) ReadUint32() uint32 {
+	end := int(r.off) + 4
+	rv := binary.LittleEndian.Uint32(r.b[int(r.off):end:end])
+	r.off += 4
+	return rv
+}
+
+func (r *Reader) ReadUint64() uint64 {
+	end := int(r.off) + 8
+	rv := binary.LittleEndian.Uint64(r.b[int(r.off):end:end])
+	r.off += 8
+	return rv
+}
+
+func (r *Reader) ReadULEB128() (value uint64) {
+	var shift uint
+
+	for {
+		b := r.b[r.off]
+		r.off++
+		value |= (uint64(b&0x7F) << shift)
+		if b&0x80 == 0 {
+			break
+		}
+		shift += 7
+	}
+	return
+}
+
+func (r *Reader) ReadString(len int64) string {
+	b := r.b[r.off : r.off+len]
+	r.off += len
+	if r.readonly {
+		return toString(b) // backed by RO memory, ok to make unsafe string
+	}
+	return string(b)
+}
+
+func toString(b []byte) string {
+	if len(b) == 0 {
+		return ""
+	}
+	return unsafe.String(&b[0], len(b))
+}
diff --git a/contrib/go/_std_1.20/src/internal/coverage/slicereader/ya.make b/contrib/go/_std_1.20/src/internal/coverage/slicereader/ya.make
new file mode 100644
index 0000000000..950964912a
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/slicereader/ya.make
@@ -0,0 +1,7 @@
+GO_LIBRARY()
+
+SRCS(
+    slicereader.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/coverage/slicewriter/slicewriter.go b/contrib/go/_std_1.20/src/internal/coverage/slicewriter/slicewriter.go
new file mode 100644
index 0000000000..3522bf5770
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/slicewriter/slicewriter.go
@@ -0,0 +1,80 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package slicewriter
+
+import (
+	"fmt"
+	"io"
+)
+
+// WriteSeeker is a helper object that implements the io.WriteSeeker
+// interface. Clients can create a WriteSeeker, make a series of Write
+// calls to add data to it (and possibly Seek calls to update
+// previously written portions), then finally invoke BytesWritten() to
+// get a pointer to the constructed byte slice.
+type WriteSeeker struct {
+	payload []byte
+	off     int64
+}
+
+func (sws *WriteSeeker) Write(p []byte) (n int, err error) {
+	amt := len(p)
+	towrite := sws.payload[sws.off:]
+	if len(towrite) < amt {
+		sws.payload = append(sws.payload, make([]byte, amt-len(towrite))...)
+		towrite = sws.payload[sws.off:]
+	}
+	copy(towrite, p)
+	sws.off += int64(amt)
+	return amt, nil
+}
+
+// Seek repositions the read/write position of the WriteSeeker within
+// its internally maintained slice. Note that it is not possible to
+// expand the size of the slice using SEEK_SET; trying to seek outside
+// the slice will result in an error.
+func (sws *WriteSeeker) Seek(offset int64, whence int) (int64, error) {
+	switch whence {
+	case io.SeekStart:
+		if sws.off != offset && (offset < 0 || offset >= int64(len(sws.payload))) {
+			return 0, fmt.Errorf("invalid seek: new offset %d (out of range [0 %d]", offset, len(sws.payload))
+		}
+		sws.off = offset
+		return offset, nil
+	case io.SeekCurrent:
+		newoff := sws.off + offset
+		if newoff != sws.off && (newoff < 0 || newoff >= int64(len(sws.payload))) {
+			return 0, fmt.Errorf("invalid seek: new offset %d (out of range [0 %d]", newoff, len(sws.payload))
+		}
+		sws.off += offset
+		return sws.off, nil
+	case io.SeekEnd:
+		newoff := int64(len(sws.payload)) + offset
+		if newoff != sws.off && (newoff < 0 || newoff >= int64(len(sws.payload))) {
+			return 0, fmt.Errorf("invalid seek: new offset %d (out of range [0 %d]", newoff, len(sws.payload))
+		}
+		sws.off = newoff
+		return sws.off, nil
+	}
+	// other modes not supported
+	return 0, fmt.Errorf("unsupported seek mode %d", whence)
+}
+
+// BytesWritten returns the underlying byte slice for the WriteSeeker,
+// containing the data written to it via Write/Seek calls.
+func (sws *WriteSeeker) BytesWritten() []byte {
+	return sws.payload
+}
+
+func (sws *WriteSeeker) Read(p []byte) (n int, err error) {
+	amt := len(p)
+	toread := sws.payload[sws.off:]
+	if len(toread) < amt {
+		amt = len(toread)
+	}
+	copy(p, toread)
+	sws.off += int64(amt)
+	return amt, nil
+}
diff --git a/contrib/go/_std_1.20/src/internal/coverage/slicewriter/ya.make b/contrib/go/_std_1.20/src/internal/coverage/slicewriter/ya.make
new file mode 100644
index 0000000000..e3169f3e1a
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/slicewriter/ya.make
@@ -0,0 +1,7 @@
+GO_LIBRARY()
+
+SRCS(
+    slicewriter.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/coverage/stringtab/stringtab.go b/contrib/go/_std_1.20/src/internal/coverage/stringtab/stringtab.go
new file mode 100644
index 0000000000..156c8ad188
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/stringtab/stringtab.go
@@ -0,0 +1,139 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package stringtab
+
+import (
+	"fmt"
+	"internal/coverage/slicereader"
+	"internal/coverage/uleb128"
+	"io"
+)
+
+// This package implements string table writer and reader utilities,
+// for use in emitting and reading/decoding coverage meta-data and
+// counter-data files.
+
+// Writer implements a string table writing utility.
+type Writer struct {
+	stab   map[string]uint32
+	strs   []string
+	tmp    []byte
+	frozen bool
+}
+
+// InitWriter initializes a stringtab.Writer.
+func (stw *Writer) InitWriter() {
+	stw.stab = make(map[string]uint32)
+	stw.tmp = make([]byte, 64)
+}
+
+// Nentries returns the number of strings interned so far.
+func (stw *Writer) Nentries() uint32 {
+	return uint32(len(stw.strs))
+}
+
+// Lookup looks up string 's' in the writer's table, adding
+// a new entry if need be, and returning an index into the table.
+func (stw *Writer) Lookup(s string) uint32 {
+	if idx, ok := stw.stab[s]; ok {
+		return idx
+	}
+	if stw.frozen {
+		panic("internal error: string table previously frozen")
+	}
+	idx := uint32(len(stw.strs))
+	stw.stab[s] = idx
+	stw.strs = append(stw.strs, s)
+	return idx
+}
+
+// Size computes the memory in bytes needed for the serialized
+// version of a stringtab.Writer.
+func (stw *Writer) Size() uint32 {
+	rval := uint32(0)
+	stw.tmp = stw.tmp[:0]
+	stw.tmp = uleb128.AppendUleb128(stw.tmp, uint(len(stw.strs)))
+	rval += uint32(len(stw.tmp))
+	for _, s := range stw.strs {
+		stw.tmp = stw.tmp[:0]
+		slen := uint(len(s))
+		stw.tmp = uleb128.AppendUleb128(stw.tmp, slen)
+		rval += uint32(len(stw.tmp)) + uint32(slen)
+	}
+	return rval
+}
+
+// Write writes the string table in serialized form to the specified
+// io.Writer.
+func (stw *Writer) Write(w io.Writer) error {
+	wr128 := func(v uint) error {
+		stw.tmp = stw.tmp[:0]
+		stw.tmp = uleb128.AppendUleb128(stw.tmp, v)
+		if nw, err := w.Write(stw.tmp); err != nil {
+			return fmt.Errorf("writing string table: %v", err)
+		} else if nw != len(stw.tmp) {
+			return fmt.Errorf("short write emitting stringtab uleb")
+		}
+		return nil
+	}
+	if err := wr128(uint(len(stw.strs))); err != nil {
+		return err
+	}
+	for _, s := range stw.strs {
+		if err := wr128(uint(len(s))); err != nil {
+			return err
+		}
+		if nw, err := w.Write([]byte(s)); err != nil {
+			return fmt.Errorf("writing string table: %v", err)
+		} else if nw != len([]byte(s)) {
+			return fmt.Errorf("short write emitting stringtab")
+		}
+	}
+	return nil
+}
+
+// Freeze sends a signal to the writer that no more additions are
+// allowed, only lookups of existing strings (if a lookup triggers
+// addition, a panic will result). Useful as a mechanism for
+// "finalizing" a string table prior to writing it out.
+func (stw *Writer) Freeze() {
+	stw.frozen = true
+}
+
+// Reader is a helper for reading a string table previously
+// serialized by a Writer.Write call.
+type Reader struct {
+	r    *slicereader.Reader
+	strs []string
+}
+
+// NewReader creates a stringtab.Reader to read the contents
+// of a string table from 'r'.
+func NewReader(r *slicereader.Reader) *Reader {
+	str := &Reader{
+		r: r,
+	}
+	return str
+}
+
+// Read reads/decodes a string table using the reader provided.
+func (str *Reader) Read() {
+	numEntries := int(str.r.ReadULEB128())
+	str.strs = make([]string, 0, numEntries)
+	for idx := 0; idx < numEntries; idx++ {
+		slen := str.r.ReadULEB128()
+		str.strs = append(str.strs, str.r.ReadString(int64(slen)))
+	}
+}
+
+// Entries returns the number of decoded entries in a string table.
+func (str *Reader) Entries() int {
+	return len(str.strs)
+}
+
+// Get returns string 'idx' within the string table.
+func (str *Reader) Get(idx uint32) string {
+	return str.strs[idx]
+}
diff --git a/contrib/go/_std_1.20/src/internal/coverage/stringtab/ya.make b/contrib/go/_std_1.20/src/internal/coverage/stringtab/ya.make
new file mode 100644
index 0000000000..805422b402
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/stringtab/ya.make
@@ -0,0 +1,7 @@
+GO_LIBRARY()
+
+SRCS(
+    stringtab.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/coverage/uleb128/uleb128.go b/contrib/go/_std_1.20/src/internal/coverage/uleb128/uleb128.go
new file mode 100644
index 0000000000..e5cd92a03e
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/uleb128/uleb128.go
@@ -0,0 +1,20 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package uleb128
+
+func AppendUleb128(b []byte, v uint) []byte {
+	for {
+		c := uint8(v & 0x7f)
+		v >>= 7
+		if v != 0 {
+			c |= 0x80
+		}
+		b = append(b, c)
+		if c&0x80 == 0 {
+			break
+		}
+	}
+	return b
+}
diff --git a/contrib/go/_std_1.20/src/internal/coverage/uleb128/ya.make b/contrib/go/_std_1.20/src/internal/coverage/uleb128/ya.make
new file mode 100644
index 0000000000..94fc7ea345
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/uleb128/ya.make
@@ -0,0 +1,7 @@
+GO_LIBRARY()
+
+SRCS(
+    uleb128.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/coverage/ya.make b/contrib/go/_std_1.20/src/internal/coverage/ya.make
new file mode 100644
index 0000000000..fba90aa775
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/coverage/ya.make
@@ -0,0 +1,26 @@
+GO_LIBRARY()
+
+SRCS(
+    cmddefs.go
+    defs.go
+    pkid.go
+)
+
+END()
+
+RECURSE(
+    calloc
+    cformat
+    cmerge
+    decodecounter
+    decodemeta
+    encodecounter
+    encodemeta
+    pods
+    rtcov
+    slicereader
+    slicewriter
+    stringtab
+    # test
+    uleb128
+)
diff --git a/contrib/go/_std_1.20/src/internal/cpu/cpu.go b/contrib/go/_std_1.20/src/internal/cpu/cpu.go
new file mode 100644
index 0000000000..aef9fb3be7
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/cpu/cpu.go
@@ -0,0 +1,223 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package cpu implements processor feature detection
+// used by the Go standard library.
+package cpu
+
+// DebugOptions is set to true by the runtime if the OS supports reading
+// GODEBUG early in runtime startup.
+// This should not be changed after it is initialized.
+var DebugOptions bool
+
+// CacheLinePad is used to pad structs to avoid false sharing.
+type CacheLinePad struct{ _ [CacheLinePadSize]byte }
+
+// CacheLineSize is the CPU's assumed cache line size.
+// There is currently no runtime detection of the real cache line size
+// so we use the constant per GOARCH CacheLinePadSize as an approximation.
+var CacheLineSize uintptr = CacheLinePadSize
+
+// The booleans in X86 contain the correspondingly named cpuid feature bit.
+// HasAVX and HasAVX2 are only set if the OS does support XMM and YMM registers
+// in addition to the cpuid feature bit being set.
+// The struct is padded to avoid false sharing.
+var X86 struct {
+	_            CacheLinePad
+	HasAES       bool
+	HasADX       bool
+	HasAVX       bool
+	HasAVX2      bool
+	HasBMI1      bool
+	HasBMI2      bool
+	HasERMS      bool
+	HasFMA       bool
+	HasOSXSAVE   bool
+	HasPCLMULQDQ bool
+	HasPOPCNT    bool
+	HasRDTSCP    bool
+	HasSHA       bool
+	HasSSE3      bool
+	HasSSSE3     bool
+	HasSSE41     bool
+	HasSSE42     bool
+	_            CacheLinePad
+}
+
+// The booleans in ARM contain the correspondingly named cpu feature bit.
+// The struct is padded to avoid false sharing.
+var ARM struct {
+	_        CacheLinePad
+	HasVFPv4 bool
+	HasIDIVA bool
+	_        CacheLinePad
+}
+
+// The booleans in ARM64 contain the correspondingly named cpu feature bit.
+// The struct is padded to avoid false sharing.
+var ARM64 struct {
+	_            CacheLinePad
+	HasAES       bool
+	HasPMULL     bool
+	HasSHA1      bool
+	HasSHA2      bool
+	HasSHA512    bool
+	HasCRC32     bool
+	HasATOMICS   bool
+	HasCPUID     bool
+	IsNeoverseN1 bool
+	IsNeoverseV1 bool
+	_            CacheLinePad
+}
+
+var MIPS64X struct {
+	_      CacheLinePad
+	HasMSA bool // MIPS SIMD architecture
+	_      CacheLinePad
+}
+
+// For ppc64(le), it is safe to check only for ISA level starting on ISA v3.00,
+// since there are no optional categories. There are some exceptions that also
+// require kernel support to work (darn, scv), so there are feature bits for
+// those as well. The minimum processor requirement is POWER8 (ISA 2.07).
+// The struct is padded to avoid false sharing.
+var PPC64 struct {
+	_         CacheLinePad
+	HasDARN   bool // Hardware random number generator (requires kernel enablement)
+	HasSCV    bool // Syscall vectored (requires kernel enablement)
+	IsPOWER8  bool // ISA v2.07 (POWER8)
+	IsPOWER9  bool // ISA v3.00 (POWER9)
+	IsPOWER10 bool // ISA v3.1  (POWER10)
+	_         CacheLinePad
+}
+
+var S390X struct {
+	_         CacheLinePad
+	HasZARCH  bool // z architecture mode is active [mandatory]
+	HasSTFLE  bool // store facility list extended [mandatory]
+	HasLDISP  bool // long (20-bit) displacements [mandatory]
+	HasEIMM   bool // 32-bit immediates [mandatory]
+	HasDFP    bool // decimal floating point
+	HasETF3EH bool // ETF-3 enhanced
+	HasMSA    bool // message security assist (CPACF)
+	HasAES    bool // KM-AES{128,192,256} functions
+	HasAESCBC bool // KMC-AES{128,192,256} functions
+	HasAESCTR bool // KMCTR-AES{128,192,256} functions
+	HasAESGCM bool // KMA-GCM-AES{128,192,256} functions
+	HasGHASH  bool // KIMD-GHASH function
+	HasSHA1   bool // K{I,L}MD-SHA-1 functions
+	HasSHA256 bool // K{I,L}MD-SHA-256 functions
+	HasSHA512 bool // K{I,L}MD-SHA-512 functions
+	HasSHA3   bool // K{I,L}MD-SHA3-{224,256,384,512} and K{I,L}MD-SHAKE-{128,256} functions
+	HasVX     bool // vector facility. Note: the runtime sets this when it processes auxv records.
+	HasVXE    bool // vector-enhancements facility 1
+	HasKDSA   bool // elliptic curve functions
+	HasECDSA  bool // NIST curves
+	HasEDDSA  bool // Edwards curves
+	_         CacheLinePad
+}
+
+// Initialize examines the processor and sets the relevant variables above.
+// This is called by the runtime package early in program initialization,
+// before normal init functions are run. env is set by runtime if the OS supports
+// cpu feature options in GODEBUG.
+func Initialize(env string) {
+	doinit()
+	processOptions(env)
+}
+
+// options contains the cpu debug options that can be used in GODEBUG.
+// Options are arch dependent and are added by the arch specific doinit functions.
+// Features that are mandatory for the specific GOARCH should not be added to options
+// (e.g. SSE2 on amd64).
+var options []option
+
+// Option names should be lower case. e.g. avx instead of AVX.
+type option struct {
+	Name      string
+	Feature   *bool
+	Specified bool // whether feature value was specified in GODEBUG
+	Enable    bool // whether feature should be enabled
+}
+
+// processOptions enables or disables CPU feature values based on the parsed env string.
+// The env string is expected to be of the form cpu.feature1=value1,cpu.feature2=value2...
+// where feature names is one of the architecture specific list stored in the
+// cpu packages options variable and values are either 'on' or 'off'.
+// If env contains cpu.all=off then all cpu features referenced through the options
+// variable are disabled. Other feature names and values result in warning messages.
+func processOptions(env string) {
+field:
+	for env != "" {
+		field := ""
+		i := indexByte(env, ',')
+		if i < 0 {
+			field, env = env, ""
+		} else {
+			field, env = env[:i], env[i+1:]
+		}
+		if len(field) < 4 || field[:4] != "cpu." {
+			continue
+		}
+		i = indexByte(field, '=')
+		if i < 0 {
+			print("GODEBUG: no value specified for \"", field, "\"\n")
+			continue
+		}
+		key, value := field[4:i], field[i+1:] // e.g. "SSE2", "on"
+
+		var enable bool
+		switch value {
+		case "on":
+			enable = true
+		case "off":
+			enable = false
+		default:
+			print("GODEBUG: value \"", value, "\" not supported for cpu option \"", key, "\"\n")
+			continue field
+		}
+
+		if key == "all" {
+			for i := range options {
+				options[i].Specified = true
+				options[i].Enable = enable
+			}
+			continue field
+		}
+
+		for i := range options {
+			if options[i].Name == key {
+				options[i].Specified = true
+				options[i].Enable = enable
+				continue field
+			}
+		}
+
+		print("GODEBUG: unknown cpu feature \"", key, "\"\n")
+	}
+
+	for _, o := range options {
+		if !o.Specified {
+			continue
+		}
+
+		if o.Enable && !*o.Feature {
+			print("GODEBUG: can not enable \"", o.Name, "\", missing CPU support\n")
+			continue
+		}
+
+		*o.Feature = o.Enable
+	}
+}
+
+// indexByte returns the index of the first instance of c in s,
+// or -1 if c is not present in s.
+func indexByte(s string, c byte) int {
+	for i := 0; i < len(s); i++ {
+		if s[i] == c {
+			return i
+		}
+	}
+	return -1
+}
diff --git a/contrib/go/_std_1.20/src/internal/cpu/cpu.s b/contrib/go/_std_1.20/src/internal/cpu/cpu.s
new file mode 100644
index 0000000000..3c770c132d
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/cpu/cpu.s
@@ -0,0 +1,6 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This assembly file exists to allow internal/cpu to call
+// non-exported runtime functions that use "go:linkname".
\ No newline at end of file
diff --git a/contrib/go/_std_1.20/src/internal/cpu/cpu_arm64.go b/contrib/go/_std_1.20/src/internal/cpu/cpu_arm64.go
new file mode 100644
index 0000000000..85210aa00c
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/cpu/cpu_arm64.go
@@ -0,0 +1,70 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package cpu
+
+// CacheLinePadSize is used to prevent false sharing of cache lines.
+// We choose 128 because Apple Silicon, a.k.a. M1, has 128-byte cache line size.
+// It doesn't cost much and is much more future-proof.
+const CacheLinePadSize = 128
+
+func doinit() {
+	options = []option{
+		{Name: "aes", Feature: &ARM64.HasAES},
+		{Name: "pmull", Feature: &ARM64.HasPMULL},
+		{Name: "sha1", Feature: &ARM64.HasSHA1},
+		{Name: "sha2", Feature: &ARM64.HasSHA2},
+		{Name: "sha512", Feature: &ARM64.HasSHA512},
+		{Name: "crc32", Feature: &ARM64.HasCRC32},
+		{Name: "atomics", Feature: &ARM64.HasATOMICS},
+		{Name: "cpuid", Feature: &ARM64.HasCPUID},
+		{Name: "isNeoverseN1", Feature: &ARM64.IsNeoverseN1},
+		{Name: "isNeoverseV1", Feature: &ARM64.IsNeoverseV1},
+	}
+
+	// arm64 uses different ways to detect CPU features at runtime depending on the operating system.
+	osInit()
+}
+
+func getisar0() uint64
+
+func getMIDR() uint64
+
+func extractBits(data uint64, start, end uint) uint {
+	return (uint)(data>>start) & ((1 << (end - start + 1)) - 1)
+}
+
+func parseARM64SystemRegisters(isar0 uint64) {
+	// ID_AA64ISAR0_EL1
+	switch extractBits(isar0, 4, 7) {
+	case 1:
+		ARM64.HasAES = true
+	case 2:
+		ARM64.HasAES = true
+		ARM64.HasPMULL = true
+	}
+
+	switch extractBits(isar0, 8, 11) {
+	case 1:
+		ARM64.HasSHA1 = true
+	}
+
+	switch extractBits(isar0, 12, 15) {
+	case 1:
+		ARM64.HasSHA2 = true
+	case 2:
+		ARM64.HasSHA2 = true
+		ARM64.HasSHA512 = true
+	}
+
+	switch extractBits(isar0, 16, 19) {
+	case 1:
+		ARM64.HasCRC32 = true
+	}
+
+	switch extractBits(isar0, 20, 23) {
+	case 2:
+		ARM64.HasATOMICS = true
+	}
+}
diff --git a/contrib/go/_std_1.20/src/internal/cpu/cpu_arm64.s b/contrib/go/_std_1.20/src/internal/cpu/cpu_arm64.s
new file mode 100644
index 0000000000..d6e7f44373
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/cpu/cpu_arm64.s
@@ -0,0 +1,18 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "textflag.h"
+
+// func getisar0() uint64
+TEXT ·getisar0(SB),NOSPLIT,$0
+	// get Instruction Set Attributes 0 into R0
+	MRS	ID_AA64ISAR0_EL1, R0
+	MOVD	R0, ret+0(FP)
+	RET
+
+// func getMIDR() uint64
+TEXT ·getMIDR(SB), NOSPLIT, $0-8
+	MRS	MIDR_EL1, R0
+	MOVD	R0, ret+0(FP)
+	RET
diff --git a/contrib/go/_std_1.20/src/internal/cpu/cpu_arm64_hwcap.go b/contrib/go/_std_1.20/src/internal/cpu/cpu_arm64_hwcap.go
new file mode 100644
index 0000000000..0fb5fb505a
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/cpu/cpu_arm64_hwcap.go
@@ -0,0 +1,62 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build arm64 && linux
+
+package cpu
+
+// HWCap may be initialized by archauxv and
+// should not be changed after it was initialized.
+var HWCap uint
+
+// HWCAP bits. These are exposed by Linux.
+const (
+	hwcap_AES     = 1 << 3
+	hwcap_PMULL   = 1 << 4
+	hwcap_SHA1    = 1 << 5
+	hwcap_SHA2    = 1 << 6
+	hwcap_CRC32   = 1 << 7
+	hwcap_ATOMICS = 1 << 8
+	hwcap_CPUID   = 1 << 11
+)
+
+func hwcapInit(os string) {
+	// HWCap was populated by the runtime from the auxiliary vector.
+	// Use HWCap information since reading aarch64 system registers
+	// is not supported in user space on older linux kernels.
+	ARM64.HasAES = isSet(HWCap, hwcap_AES)
+	ARM64.HasPMULL = isSet(HWCap, hwcap_PMULL)
+	ARM64.HasSHA1 = isSet(HWCap, hwcap_SHA1)
+	ARM64.HasSHA2 = isSet(HWCap, hwcap_SHA2)
+	ARM64.HasCRC32 = isSet(HWCap, hwcap_CRC32)
+	ARM64.HasCPUID = isSet(HWCap, hwcap_CPUID)
+
+	// The Samsung S9+ kernel reports support for atomics, but not all cores
+	// actually support them, resulting in SIGILL. See issue #28431.
+	// TODO(elias.naur): Only disable the optimization on bad chipsets on android.
+	ARM64.HasATOMICS = isSet(HWCap, hwcap_ATOMICS) && os != "android"
+
+	// Check to see if executing on a NeoverseN1 and in order to do that,
+	// check the AUXV for the CPUID bit. The getMIDR function executes an
+	// instruction which would normally be an illegal instruction, but it's
+	// trapped by the kernel, the value sanitized and then returned. Without
+	// the CPUID bit the kernel will not trap the instruction and the process
+	// will be terminated with SIGILL.
+	if ARM64.HasCPUID {
+		midr := getMIDR()
+		part_num := uint16((midr >> 4) & 0xfff)
+		implementor := byte((midr >> 24) & 0xff)
+
+		if implementor == 'A' && part_num == 0xd0c {
+			ARM64.IsNeoverseN1 = true
+		}
+		if implementor == 'A' && part_num == 0xd40 {
+			ARM64.IsNeoverseV1 = true
+		}
+	}
+}
+
+func isSet(hwc uint, value uint) bool {
+	return hwc&value != 0
+}
diff --git a/contrib/go/_std_1.20/src/internal/cpu/cpu_arm64_linux.go b/contrib/go/_std_1.20/src/internal/cpu/cpu_arm64_linux.go
new file mode 100644
index 0000000000..d746bdb063
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/cpu/cpu_arm64_linux.go
@@ -0,0 +1,11 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build arm64 && linux && !android
+
+package cpu
+
+func osInit() {
+	hwcapInit("linux")
+}
diff --git a/contrib/go/_std_1.20/src/internal/cpu/cpu_no_name.go b/contrib/go/_std_1.20/src/internal/cpu/cpu_no_name.go
new file mode 100644
index 0000000000..2adfa1b709
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/cpu/cpu_no_name.go
@@ -0,0 +1,18 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !386 && !amd64 && !ppc64 && !ppc64le
+
+package cpu
+
+// Name returns the CPU name given by the vendor
+// if it can be read directly from memory or by CPU instructions.
+// If the CPU name can not be determined an empty string is returned.
+//
+// Implementations that use the Operating System (e.g. sysctl or /sys/)
+// to gather CPU information for display should be placed in internal/sysinfo.
+func Name() string {
+	// "A CPU has no name".
+	return ""
+}
diff --git a/contrib/go/_std_1.20/src/internal/cpu/cpu_x86.go b/contrib/go/_std_1.20/src/internal/cpu/cpu_x86.go
new file mode 100644
index 0000000000..96b8ef92b5
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/cpu/cpu_x86.go
@@ -0,0 +1,190 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build 386 || amd64
+
+package cpu
+
+const CacheLinePadSize = 64
+
+// cpuid is implemented in cpu_x86.s.
+func cpuid(eaxArg, ecxArg uint32) (eax, ebx, ecx, edx uint32)
+
+// xgetbv with ecx = 0 is implemented in cpu_x86.s.
+func xgetbv() (eax, edx uint32)
+
+// getGOAMD64level is implemented in cpu_x86.s. Returns number in [1,4].
+func getGOAMD64level() int32
+
+const (
+	// edx bits
+	cpuid_SSE2 = 1 << 26
+
+	// ecx bits
+	cpuid_SSE3      = 1 << 0
+	cpuid_PCLMULQDQ = 1 << 1
+	cpuid_SSSE3     = 1 << 9
+	cpuid_FMA       = 1 << 12
+	cpuid_SSE41     = 1 << 19
+	cpuid_SSE42     = 1 << 20
+	cpuid_POPCNT    = 1 << 23
+	cpuid_AES       = 1 << 25
+	cpuid_OSXSAVE   = 1 << 27
+	cpuid_AVX       = 1 << 28
+
+	// ebx bits
+	cpuid_BMI1 = 1 << 3
+	cpuid_AVX2 = 1 << 5
+	cpuid_BMI2 = 1 << 8
+	cpuid_ERMS = 1 << 9
+	cpuid_ADX  = 1 << 19
+	cpuid_SHA  = 1 << 29
+
+	// edx bits for CPUID 0x80000001
+	cpuid_RDTSCP = 1 << 27
+)
+
+var maxExtendedFunctionInformation uint32
+
+func doinit() {
+	options = []option{
+		{Name: "adx", Feature: &X86.HasADX},
+		{Name: "aes", Feature: &X86.HasAES},
+		{Name: "erms", Feature: &X86.HasERMS},
+		{Name: "pclmulqdq", Feature: &X86.HasPCLMULQDQ},
+		{Name: "rdtscp", Feature: &X86.HasRDTSCP},
+		{Name: "sha", Feature: &X86.HasSHA},
+	}
+	level := getGOAMD64level()
+	if level < 2 {
+		// These options are required at level 2. At lower levels
+		// they can be turned off.
+		options = append(options,
+			option{Name: "popcnt", Feature: &X86.HasPOPCNT},
+			option{Name: "sse3", Feature: &X86.HasSSE3},
+			option{Name: "sse41", Feature: &X86.HasSSE41},
+			option{Name: "sse42", Feature: &X86.HasSSE42},
+			option{Name: "ssse3", Feature: &X86.HasSSSE3})
+	}
+	if level < 3 {
+		// These options are required at level 3. At lower levels
+		// they can be turned off.
+		options = append(options,
+			option{Name: "avx", Feature: &X86.HasAVX},
+			option{Name: "avx2", Feature: &X86.HasAVX2},
+			option{Name: "bmi1", Feature: &X86.HasBMI1},
+			option{Name: "bmi2", Feature: &X86.HasBMI2},
+			option{Name: "fma", Feature: &X86.HasFMA})
+	}
+
+	maxID, _, _, _ := cpuid(0, 0)
+
+	if maxID < 1 {
+		return
+	}
+
+	maxExtendedFunctionInformation, _, _, _ = cpuid(0x80000000, 0)
+
+	_, _, ecx1, _ := cpuid(1, 0)
+
+	X86.HasSSE3 = isSet(ecx1, cpuid_SSE3)
+	X86.HasPCLMULQDQ = isSet(ecx1, cpuid_PCLMULQDQ)
+	X86.HasSSSE3 = isSet(ecx1, cpuid_SSSE3)
+	X86.HasSSE41 = isSet(ecx1, cpuid_SSE41)
+	X86.HasSSE42 = isSet(ecx1, cpuid_SSE42)
+	X86.HasPOPCNT = isSet(ecx1, cpuid_POPCNT)
+	X86.HasAES = isSet(ecx1, cpuid_AES)
+
+	// OSXSAVE can be false when using older Operating Systems
+	// or when explicitly disabled on newer Operating Systems by
+	// e.g. setting the xsavedisable boot option on Windows 10.
+	X86.HasOSXSAVE = isSet(ecx1, cpuid_OSXSAVE)
+
+	// The FMA instruction set extension only has VEX prefixed instructions.
+	// VEX prefixed instructions require OSXSAVE to be enabled.
+	// See Intel 64 and IA-32 Architecture Software Developer’s Manual Volume 2
+	// Section 2.4 "AVX and SSE Instruction Exception Specification"
+	X86.HasFMA = isSet(ecx1, cpuid_FMA) && X86.HasOSXSAVE
+
+	osSupportsAVX := false
+	// For XGETBV, OSXSAVE bit is required and sufficient.
+	if X86.HasOSXSAVE {
+		eax, _ := xgetbv()
+		// Check if XMM and YMM registers have OS support.
+		osSupportsAVX = isSet(eax, 1<<1) && isSet(eax, 1<<2)
+	}
+
+	X86.HasAVX = isSet(ecx1, cpuid_AVX) && osSupportsAVX
+
+	if maxID < 7 {
+		return
+	}
+
+	_, ebx7, _, _ := cpuid(7, 0)
+	X86.HasBMI1 = isSet(ebx7, cpuid_BMI1)
+	X86.HasAVX2 = isSet(ebx7, cpuid_AVX2) && osSupportsAVX
+	X86.HasBMI2 = isSet(ebx7, cpuid_BMI2)
+	X86.HasERMS = isSet(ebx7, cpuid_ERMS)
+	X86.HasADX = isSet(ebx7, cpuid_ADX)
+	X86.HasSHA = isSet(ebx7, cpuid_SHA)
+
+	var maxExtendedInformation uint32
+	maxExtendedInformation, _, _, _ = cpuid(0x80000000, 0)
+
+	if maxExtendedInformation < 0x80000001 {
+		return
+	}
+
+	_, _, _, edxExt1 := cpuid(0x80000001, 0)
+	X86.HasRDTSCP = isSet(edxExt1, cpuid_RDTSCP)
+}
+
+func isSet(hwc uint32, value uint32) bool {
+	return hwc&value != 0
+}
+
+// Name returns the CPU name given by the vendor.
+// If the CPU name can not be determined an
+// empty string is returned.
+func Name() string {
+	if maxExtendedFunctionInformation < 0x80000004 {
+		return ""
+	}
+
+	data := make([]byte, 0, 3*4*4)
+
+	var eax, ebx, ecx, edx uint32
+	eax, ebx, ecx, edx = cpuid(0x80000002, 0)
+	data = appendBytes(data, eax, ebx, ecx, edx)
+	eax, ebx, ecx, edx = cpuid(0x80000003, 0)
+	data = appendBytes(data, eax, ebx, ecx, edx)
+	eax, ebx, ecx, edx = cpuid(0x80000004, 0)
+	data = appendBytes(data, eax, ebx, ecx, edx)
+
+	// Trim leading spaces.
+	for len(data) > 0 && data[0] == ' ' {
+		data = data[1:]
+	}
+
+	// Trim tail after and including the first null byte.
+	for i, c := range data {
+		if c == '\x00' {
+			data = data[:i]
+			break
+		}
+	}
+
+	return string(data)
+}
+
+func appendBytes(b []byte, args ...uint32) []byte {
+	for _, arg := range args {
+		b = append(b,
+			byte((arg >> 0)),
+			byte((arg >> 8)),
+			byte((arg >> 16)),
+			byte((arg >> 24)))
+	}
+	return b
+}
diff --git a/contrib/go/_std_1.20/src/internal/cpu/cpu_x86.s b/contrib/go/_std_1.20/src/internal/cpu/cpu_x86.s
new file mode 100644
index 0000000000..2ee8eca248
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/cpu/cpu_x86.s
@@ -0,0 +1,43 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build 386 || amd64
+
+#include "textflag.h"
+
+// func cpuid(eaxArg, ecxArg uint32) (eax, ebx, ecx, edx uint32)
+TEXT ·cpuid(SB), NOSPLIT, $0-24
+	MOVL eaxArg+0(FP), AX
+	MOVL ecxArg+4(FP), CX
+	CPUID
+	MOVL AX, eax+8(FP)
+	MOVL BX, ebx+12(FP)
+	MOVL CX, ecx+16(FP)
+	MOVL DX, edx+20(FP)
+	RET
+
+// func xgetbv() (eax, edx uint32)
+TEXT ·xgetbv(SB),NOSPLIT,$0-8
+	MOVL $0, CX
+	XGETBV
+	MOVL AX, eax+0(FP)
+	MOVL DX, edx+4(FP)
+	RET
+
+// func getGOAMD64level() int32
+TEXT ·getGOAMD64level(SB),NOSPLIT,$0-4
+#ifdef GOAMD64_v4
+	MOVL $4, ret+0(FP)
+#else
+#ifdef GOAMD64_v3
+	MOVL $3, ret+0(FP)
+#else
+#ifdef GOAMD64_v2
+	MOVL $2, ret+0(FP)
+#else
+	MOVL $1, ret+0(FP)
+#endif
+#endif
+#endif
+	RET
diff --git a/contrib/go/_std_1.20/src/internal/cpu/ya.make b/contrib/go/_std_1.20/src/internal/cpu/ya.make
new file mode 100644
index 0000000000..fbaac454b3
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/cpu/ya.make
@@ -0,0 +1,42 @@
+GO_LIBRARY()
+
+SRCS(
+    cpu.go
+    cpu.s
+)
+
+IF (ARCH_ARM64)
+    SRCS(
+        cpu_arm64.go
+        cpu_arm64.s
+        cpu_no_name.go
+    )
+ENDIF()
+
+IF (ARCH_X86_64)
+    SRCS(
+        cpu_x86.go
+        cpu_x86.s
+    )
+ENDIF()
+
+IF (OS_DARWIN AND ARCH_ARM64)
+    SRCS(
+        cpu_arm64_darwin.go
+    )
+ENDIF()
+
+IF (OS_LINUX AND ARCH_ARM64)
+    SRCS(
+        cpu_arm64_hwcap.go
+        cpu_arm64_linux.go
+    )
+ENDIF()
+
+IF (OS_WINDOWS AND ARCH_ARM64)
+    SRCS(
+        cpu_arm64_other.go
+    )
+ENDIF()
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/fmtsort/sort.go b/contrib/go/_std_1.20/src/internal/fmtsort/sort.go
new file mode 100644
index 0000000000..278a89bd75
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/fmtsort/sort.go
@@ -0,0 +1,219 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package fmtsort provides a general stable ordering mechanism
+// for maps, on behalf of the fmt and text/template packages.
+// It is not guaranteed to be efficient and works only for types
+// that are valid map keys.
+package fmtsort
+
+import (
+	"reflect"
+	"sort"
+)
+
+// Note: Throughout this package we avoid calling reflect.Value.Interface as
+// it is not always legal to do so and it's easier to avoid the issue than to face it.
+
+// SortedMap represents a map's keys and values. The keys and values are
+// aligned in index order: Value[i] is the value in the map corresponding to Key[i].
+type SortedMap struct {
+	Key   []reflect.Value
+	Value []reflect.Value
+}
+
+func (o *SortedMap) Len() int           { return len(o.Key) }
+func (o *SortedMap) Less(i, j int) bool { return compare(o.Key[i], o.Key[j]) < 0 }
+func (o *SortedMap) Swap(i, j int) {
+	o.Key[i], o.Key[j] = o.Key[j], o.Key[i]
+	o.Value[i], o.Value[j] = o.Value[j], o.Value[i]
+}
+
+// Sort accepts a map and returns a SortedMap that has the same keys and
+// values but in a stable sorted order according to the keys, modulo issues
+// raised by unorderable key values such as NaNs.
+//
+// The ordering rules are more general than with Go's < operator:
+//
+//   - when applicable, nil compares low
+//   - ints, floats, and strings order by <
+//   - NaN compares less than non-NaN floats
+//   - bool compares false before true
+//   - complex compares real, then imag
+//   - pointers compare by machine address
+//   - channel values compare by machine address
+//   - structs compare each field in turn
+//   - arrays compare each element in turn.
+//     Otherwise identical arrays compare by length.
+//   - interface values compare first by reflect.Type describing the concrete type
+//     and then by concrete value as described in the previous rules.
+func Sort(mapValue reflect.Value) *SortedMap {
+	if mapValue.Type().Kind() != reflect.Map {
+		return nil
+	}
+	// Note: this code is arranged to not panic even in the presence
+	// of a concurrent map update. The runtime is responsible for
+	// yelling loudly if that happens. See issue 33275.
+	n := mapValue.Len()
+	key := make([]reflect.Value, 0, n)
+	value := make([]reflect.Value, 0, n)
+	iter := mapValue.MapRange()
+	for iter.Next() {
+		key = append(key, iter.Key())
+		value = append(value, iter.Value())
+	}
+	sorted := &SortedMap{
+		Key:   key,
+		Value: value,
+	}
+	sort.Stable(sorted)
+	return sorted
+}
+
+// compare compares two values of the same type. It returns -1, 0, 1
+// according to whether a > b (1), a == b (0), or a < b (-1).
+// If the types differ, it returns -1.
+// See the comment on Sort for the comparison rules.
+func compare(aVal, bVal reflect.Value) int {
+	aType, bType := aVal.Type(), bVal.Type()
+	if aType != bType {
+		return -1 // No good answer possible, but don't return 0: they're not equal.
+	}
+	switch aVal.Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		a, b := aVal.Int(), bVal.Int()
+		switch {
+		case a < b:
+			return -1
+		case a > b:
+			return 1
+		default:
+			return 0
+		}
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		a, b := aVal.Uint(), bVal.Uint()
+		switch {
+		case a < b:
+			return -1
+		case a > b:
+			return 1
+		default:
+			return 0
+		}
+	case reflect.String:
+		a, b := aVal.String(), bVal.String()
+		switch {
+		case a < b:
+			return -1
+		case a > b:
+			return 1
+		default:
+			return 0
+		}
+	case reflect.Float32, reflect.Float64:
+		return floatCompare(aVal.Float(), bVal.Float())
+	case reflect.Complex64, reflect.Complex128:
+		a, b := aVal.Complex(), bVal.Complex()
+		if c := floatCompare(real(a), real(b)); c != 0 {
+			return c
+		}
+		return floatCompare(imag(a), imag(b))
+	case reflect.Bool:
+		a, b := aVal.Bool(), bVal.Bool()
+		switch {
+		case a == b:
+			return 0
+		case a:
+			return 1
+		default:
+			return -1
+		}
+	case reflect.Pointer, reflect.UnsafePointer:
+		a, b := aVal.Pointer(), bVal.Pointer()
+		switch {
+		case a < b:
+			return -1
+		case a > b:
+			return 1
+		default:
+			return 0
+		}
+	case reflect.Chan:
+		if c, ok := nilCompare(aVal, bVal); ok {
+			return c
+		}
+		ap, bp := aVal.Pointer(), bVal.Pointer()
+		switch {
+		case ap < bp:
+			return -1
+		case ap > bp:
+			return 1
+		default:
+			return 0
+		}
+	case reflect.Struct:
+		for i := 0; i < aVal.NumField(); i++ {
+			if c := compare(aVal.Field(i), bVal.Field(i)); c != 0 {
+				return c
+			}
+		}
+		return 0
+	case reflect.Array:
+		for i := 0; i < aVal.Len(); i++ {
+			if c := compare(aVal.Index(i), bVal.Index(i)); c != 0 {
+				return c
+			}
+		}
+		return 0
+	case reflect.Interface:
+		if c, ok := nilCompare(aVal, bVal); ok {
+			return c
+		}
+		c := compare(reflect.ValueOf(aVal.Elem().Type()), reflect.ValueOf(bVal.Elem().Type()))
+		if c != 0 {
+			return c
+		}
+		return compare(aVal.Elem(), bVal.Elem())
+	default:
+		// Certain types cannot appear as keys (maps, funcs, slices), but be explicit.
+		panic("bad type in compare: " + aType.String())
+	}
+}
+
+// nilCompare checks whether either value is nil. If not, the boolean is false.
+// If either value is nil, the boolean is true and the integer is the comparison
+// value. The comparison is defined to be 0 if both are nil, otherwise the one
+// nil value compares low. Both arguments must represent a chan, func,
+// interface, map, pointer, or slice.
+func nilCompare(aVal, bVal reflect.Value) (int, bool) {
+	if aVal.IsNil() {
+		if bVal.IsNil() {
+			return 0, true
+		}
+		return -1, true
+	}
+	if bVal.IsNil() {
+		return 1, true
+	}
+	return 0, false
+}
+
+// floatCompare compares two floating-point values. NaNs compare low.
+func floatCompare(a, b float64) int {
+	switch {
+	case isNaN(a):
+		return -1 // No good answer if b is a NaN so don't bother checking.
+	case isNaN(b):
+		return 1
+	case a < b:
+		return -1
+	case a > b:
+		return 1
+	}
+	return 0
+}
+
+func isNaN(a float64) bool {
+	return a != a
+}
diff --git a/contrib/go/_std_1.20/src/internal/fmtsort/ya.make b/contrib/go/_std_1.20/src/internal/fmtsort/ya.make
new file mode 100644
index 0000000000..cf99850591
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/fmtsort/ya.make
@@ -0,0 +1,7 @@
+GO_LIBRARY()
+
+SRCS(
+    sort.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/fuzz/counters_supported.go b/contrib/go/_std_1.20/src/internal/fuzz/counters_supported.go
new file mode 100644
index 0000000000..79e27d27e1
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/fuzz/counters_supported.go
@@ -0,0 +1,21 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build (darwin || linux || windows || freebsd) && (amd64 || arm64)
+
+package fuzz
+
+import (
+	"unsafe"
+)
+
+// coverage returns a []byte containing unique 8-bit counters for each edge of
+// the instrumented source code. This coverage data will only be generated if
+// `-d=libfuzzer` is set at build time. This can be used to understand the code
+// coverage of a test execution.
+func coverage() []byte {
+	addr := unsafe.Pointer(&_counters)
+	size := uintptr(unsafe.Pointer(&_ecounters)) - uintptr(addr)
+	return unsafe.Slice((*byte)(addr), int(size))
+}
diff --git a/contrib/go/_std_1.20/src/internal/fuzz/coverage.go b/contrib/go/_std_1.20/src/internal/fuzz/coverage.go
new file mode 100644
index 0000000000..0c5e17e3bb
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/fuzz/coverage.go
@@ -0,0 +1,107 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package fuzz
+
+import (
+	"fmt"
+	"math/bits"
+)
+
+// ResetCoverage sets all of the counters for each edge of the instrumented
+// source code to 0.
+func ResetCoverage() {
+	cov := coverage()
+	for i := range cov {
+		cov[i] = 0
+	}
+}
+
+// SnapshotCoverage copies the current counter values into coverageSnapshot,
+// preserving them for later inspection. SnapshotCoverage also rounds each
+// counter down to the nearest power of two. This lets the coordinator store
+// multiple values for each counter by OR'ing them together.
+func SnapshotCoverage() {
+	cov := coverage()
+	for i, b := range cov {
+		b |= b >> 1
+		b |= b >> 2
+		b |= b >> 4
+		b -= b >> 1
+		coverageSnapshot[i] = b
+	}
+}
+
+// diffCoverage returns a set of bits set in snapshot but not in base.
+// If there are no new bits set, diffCoverage returns nil.
+func diffCoverage(base, snapshot []byte) []byte {
+	if len(base) != len(snapshot) {
+		panic(fmt.Sprintf("the number of coverage bits changed: before=%d, after=%d", len(base), len(snapshot)))
+	}
+	found := false
+	for i := range snapshot {
+		if snapshot[i]&^base[i] != 0 {
+			found = true
+			break
+		}
+	}
+	if !found {
+		return nil
+	}
+	diff := make([]byte, len(snapshot))
+	for i := range diff {
+		diff[i] = snapshot[i] &^ base[i]
+	}
+	return diff
+}
+
+// countNewCoverageBits returns the number of bits set in snapshot that are not
+// set in base.
+func countNewCoverageBits(base, snapshot []byte) int {
+	n := 0
+	for i := range snapshot {
+		n += bits.OnesCount8(snapshot[i] &^ base[i])
+	}
+	return n
+}
+
+// isCoverageSubset returns true if all the base coverage bits are set in
+// snapshot.
+func isCoverageSubset(base, snapshot []byte) bool {
+	for i, v := range base {
+		if v&snapshot[i] != v {
+			return false
+		}
+	}
+	return true
+}
+
+// hasCoverageBit returns true if snapshot has at least one bit set that is
+// also set in base.
+func hasCoverageBit(base, snapshot []byte) bool {
+	for i := range snapshot {
+		if snapshot[i]&base[i] != 0 {
+			return true
+		}
+	}
+	return false
+}
+
+func countBits(cov []byte) int {
+	n := 0
+	for _, c := range cov {
+		n += bits.OnesCount8(c)
+	}
+	return n
+}
+
+var (
+	coverageEnabled  = len(coverage()) > 0
+	coverageSnapshot = make([]byte, len(coverage()))
+
+	// _counters and _ecounters mark the start and end, respectively, of where
+	// the 8-bit coverage counters reside in memory. They're known to cmd/link,
+	// which specially assigns their addresses for this purpose.
+	_counters, _ecounters [0]byte
+)
diff --git a/contrib/go/_std_1.20/src/internal/fuzz/encoding.go b/contrib/go/_std_1.20/src/internal/fuzz/encoding.go
new file mode 100644
index 0000000000..270ef7a1a3
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/fuzz/encoding.go
@@ -0,0 +1,361 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package fuzz
+
+import (
+	"bytes"
+	"fmt"
+	"go/ast"
+	"go/parser"
+	"go/token"
+	"math"
+	"strconv"
+	"strings"
+	"unicode/utf8"
+)
+
+// encVersion1 will be the first line of a file with version 1 encoding.
+var encVersion1 = "go test fuzz v1"
+
+// marshalCorpusFile encodes an arbitrary number of arguments into the file format for the
+// corpus.
+func marshalCorpusFile(vals ...any) []byte {
+	if len(vals) == 0 {
+		panic("must have at least one value to marshal")
+	}
+	b := bytes.NewBuffer([]byte(encVersion1 + "\n"))
+	// TODO(katiehockman): keep uint8 and int32 encoding where applicable,
+	// instead of changing to byte and rune respectively.
+	for _, val := range vals {
+		switch t := val.(type) {
+		case int, int8, int16, int64, uint, uint16, uint32, uint64, bool:
+			fmt.Fprintf(b, "%T(%v)\n", t, t)
+		case float32:
+			if math.IsNaN(float64(t)) && math.Float32bits(t) != math.Float32bits(float32(math.NaN())) {
+				// We encode unusual NaNs as hex values, because that is how users are
+				// likely to encounter them in literature about floating-point encoding.
+				// This allows us to reproduce fuzz failures that depend on the specific
+				// NaN representation (for float32 there are about 2^24 possibilities!),
+				// not just the fact that the value is *a* NaN.
+				//
+				// Note that the specific value of float32(math.NaN()) can vary based on
+				// whether the architecture represents signaling NaNs using a low bit
+				// (as is common) or a high bit (as commonly implemented on MIPS
+				// hardware before around 2012). We believe that the increase in clarity
+				// from identifying "NaN" with math.NaN() is worth the slight ambiguity
+				// from a platform-dependent value.
+				fmt.Fprintf(b, "math.Float32frombits(0x%x)\n", math.Float32bits(t))
+			} else {
+				// We encode all other values — including the NaN value that is
+				// bitwise-identical to float32(math.Nan()) — using the default
+				// formatting, which is equivalent to strconv.FormatFloat with format
+				// 'g' and can be parsed by strconv.ParseFloat.
+				//
+				// For an ordinary floating-point number this format includes
+				// sufficiently many digits to reconstruct the exact value. For positive
+				// or negative infinity it is the string "+Inf" or "-Inf". For positive
+				// or negative zero it is "0" or "-0". For NaN, it is the string "NaN".
+				fmt.Fprintf(b, "%T(%v)\n", t, t)
+			}
+		case float64:
+			if math.IsNaN(t) && math.Float64bits(t) != math.Float64bits(math.NaN()) {
+				fmt.Fprintf(b, "math.Float64frombits(0x%x)\n", math.Float64bits(t))
+			} else {
+				fmt.Fprintf(b, "%T(%v)\n", t, t)
+			}
+		case string:
+			fmt.Fprintf(b, "string(%q)\n", t)
+		case rune: // int32
+			// Although rune and int32 are represented by the same type, only a subset
+			// of valid int32 values can be expressed as rune literals. Notably,
+			// negative numbers, surrogate halves, and values above unicode.MaxRune
+			// have no quoted representation.
+			//
+			// fmt with "%q" (and the corresponding functions in the strconv package)
+			// would quote out-of-range values to the Unicode replacement character
+			// instead of the original value (see https://go.dev/issue/51526), so
+			// they must be treated as int32 instead.
+			//
+			// We arbitrarily draw the line at UTF-8 validity, which biases toward the
+			// "rune" interpretation. (However, we accept either format as input.)
+			if utf8.ValidRune(t) {
+				fmt.Fprintf(b, "rune(%q)\n", t)
+			} else {
+				fmt.Fprintf(b, "int32(%v)\n", t)
+			}
+		case byte: // uint8
+			// For bytes, we arbitrarily prefer the character interpretation.
+			// (Every byte has a valid character encoding.)
+			fmt.Fprintf(b, "byte(%q)\n", t)
+		case []byte: // []uint8
+			fmt.Fprintf(b, "[]byte(%q)\n", t)
+		default:
+			panic(fmt.Sprintf("unsupported type: %T", t))
+		}
+	}
+	return b.Bytes()
+}
+
+// unmarshalCorpusFile decodes corpus bytes into their respective values.
+func unmarshalCorpusFile(b []byte) ([]any, error) {
+	if len(b) == 0 {
+		return nil, fmt.Errorf("cannot unmarshal empty string")
+	}
+	lines := bytes.Split(b, []byte("\n"))
+	if len(lines) < 2 {
+		return nil, fmt.Errorf("must include version and at least one value")
+	}
+	version := strings.TrimSuffix(string(lines[0]), "\r")
+	if version != encVersion1 {
+		return nil, fmt.Errorf("unknown encoding version: %s", version)
+	}
+	var vals []any
+	for _, line := range lines[1:] {
+		line = bytes.TrimSpace(line)
+		if len(line) == 0 {
+			continue
+		}
+		v, err := parseCorpusValue(line)
+		if err != nil {
+			return nil, fmt.Errorf("malformed line %q: %v", line, err)
+		}
+		vals = append(vals, v)
+	}
+	return vals, nil
+}
+
+func parseCorpusValue(line []byte) (any, error) {
+	fs := token.NewFileSet()
+	expr, err := parser.ParseExprFrom(fs, "(test)", line, 0)
+	if err != nil {
+		return nil, err
+	}
+	call, ok := expr.(*ast.CallExpr)
+	if !ok {
+		return nil, fmt.Errorf("expected call expression")
+	}
+	if len(call.Args) != 1 {
+		return nil, fmt.Errorf("expected call expression with 1 argument; got %d", len(call.Args))
+	}
+	arg := call.Args[0]
+
+	if arrayType, ok := call.Fun.(*ast.ArrayType); ok {
+		if arrayType.Len != nil {
+			return nil, fmt.Errorf("expected []byte or primitive type")
+		}
+		elt, ok := arrayType.Elt.(*ast.Ident)
+		if !ok || elt.Name != "byte" {
+			return nil, fmt.Errorf("expected []byte")
+		}
+		lit, ok := arg.(*ast.BasicLit)
+		if !ok || lit.Kind != token.STRING {
+			return nil, fmt.Errorf("string literal required for type []byte")
+		}
+		s, err := strconv.Unquote(lit.Value)
+		if err != nil {
+			return nil, err
+		}
+		return []byte(s), nil
+	}
+
+	var idType *ast.Ident
+	if selector, ok := call.Fun.(*ast.SelectorExpr); ok {
+		xIdent, ok := selector.X.(*ast.Ident)
+		if !ok || xIdent.Name != "math" {
+			return nil, fmt.Errorf("invalid selector type")
+		}
+		switch selector.Sel.Name {
+		case "Float64frombits":
+			idType = &ast.Ident{Name: "float64-bits"}
+		case "Float32frombits":
+			idType = &ast.Ident{Name: "float32-bits"}
+		default:
+			return nil, fmt.Errorf("invalid selector type")
+		}
+	} else {
+		idType, ok = call.Fun.(*ast.Ident)
+		if !ok {
+			return nil, fmt.Errorf("expected []byte or primitive type")
+		}
+		if idType.Name == "bool" {
+			id, ok := arg.(*ast.Ident)
+			if !ok {
+				return nil, fmt.Errorf("malformed bool")
+			}
+			if id.Name == "true" {
+				return true, nil
+			} else if id.Name == "false" {
+				return false, nil
+			} else {
+				return nil, fmt.Errorf("true or false required for type bool")
+			}
+		}
+	}
+
+	var (
+		val  string
+		kind token.Token
+	)
+	if op, ok := arg.(*ast.UnaryExpr); ok {
+		switch lit := op.X.(type) {
+		case *ast.BasicLit:
+			if op.Op != token.SUB {
+				return nil, fmt.Errorf("unsupported operation on int/float: %v", op.Op)
+			}
+			// Special case for negative numbers.
+			val = op.Op.String() + lit.Value // e.g. "-" + "124"
+			kind = lit.Kind
+		case *ast.Ident:
+			if lit.Name != "Inf" {
+				return nil, fmt.Errorf("expected operation on int or float type")
+			}
+			if op.Op == token.SUB {
+				val = "-Inf"
+			} else {
+				val = "+Inf"
+			}
+			kind = token.FLOAT
+		default:
+			return nil, fmt.Errorf("expected operation on int or float type")
+		}
+	} else {
+		switch lit := arg.(type) {
+		case *ast.BasicLit:
+			val, kind = lit.Value, lit.Kind
+		case *ast.Ident:
+			if lit.Name != "NaN" {
+				return nil, fmt.Errorf("literal value required for primitive type")
+			}
+			val, kind = "NaN", token.FLOAT
+		default:
+			return nil, fmt.Errorf("literal value required for primitive type")
+		}
+	}
+
+	switch typ := idType.Name; typ {
+	case "string":
+		if kind != token.STRING {
+			return nil, fmt.Errorf("string literal value required for type string")
+		}
+		return strconv.Unquote(val)
+	case "byte", "rune":
+		if kind == token.INT {
+			switch typ {
+			case "rune":
+				return parseInt(val, typ)
+			case "byte":
+				return parseUint(val, typ)
+			}
+		}
+		if kind != token.CHAR {
+			return nil, fmt.Errorf("character literal required for byte/rune types")
+		}
+		n := len(val)
+		if n < 2 {
+			return nil, fmt.Errorf("malformed character literal, missing single quotes")
+		}
+		code, _, _, err := strconv.UnquoteChar(val[1:n-1], '\'')
+		if err != nil {
+			return nil, err
+		}
+		if typ == "rune" {
+			return code, nil
+		}
+		if code >= 256 {
+			return nil, fmt.Errorf("can only encode single byte to a byte type")
+		}
+		return byte(code), nil
+	case "int", "int8", "int16", "int32", "int64":
+		if kind != token.INT {
+			return nil, fmt.Errorf("integer literal required for int types")
+		}
+		return parseInt(val, typ)
+	case "uint", "uint8", "uint16", "uint32", "uint64":
+		if kind != token.INT {
+			return nil, fmt.Errorf("integer literal required for uint types")
+		}
+		return parseUint(val, typ)
+	case "float32":
+		if kind != token.FLOAT && kind != token.INT {
+			return nil, fmt.Errorf("float or integer literal required for float32 type")
+		}
+		v, err := strconv.ParseFloat(val, 32)
+		return float32(v), err
+	case "float64":
+		if kind != token.FLOAT && kind != token.INT {
+			return nil, fmt.Errorf("float or integer literal required for float64 type")
+		}
+		return strconv.ParseFloat(val, 64)
+	case "float32-bits":
+		if kind != token.INT {
+			return nil, fmt.Errorf("integer literal required for math.Float32frombits type")
+		}
+		bits, err := parseUint(val, "uint32")
+		if err != nil {
+			return nil, err
+		}
+		return math.Float32frombits(bits.(uint32)), nil
+	case "float64-bits":
+		if kind != token.FLOAT && kind != token.INT {
+			return nil, fmt.Errorf("integer literal required for math.Float64frombits type")
+		}
+		bits, err := parseUint(val, "uint64")
+		if err != nil {
+			return nil, err
+		}
+		return math.Float64frombits(bits.(uint64)), nil
+	default:
+		return nil, fmt.Errorf("expected []byte or primitive type")
+	}
+}
+
+// parseInt returns an integer of value val and type typ.
+func parseInt(val, typ string) (any, error) {
+	switch typ {
+	case "int":
+		// The int type may be either 32 or 64 bits. If 32, the fuzz tests in the
+		// corpus may include 64-bit values produced by fuzzing runs on 64-bit
+		// architectures. When running those tests, we implicitly wrap the values to
+		// fit in a regular int. (The test case is still “interesting”, even if the
+		// specific values of its inputs are platform-dependent.)
+		i, err := strconv.ParseInt(val, 0, 64)
+		return int(i), err
+	case "int8":
+		i, err := strconv.ParseInt(val, 0, 8)
+		return int8(i), err
+	case "int16":
+		i, err := strconv.ParseInt(val, 0, 16)
+		return int16(i), err
+	case "int32", "rune":
+		i, err := strconv.ParseInt(val, 0, 32)
+		return int32(i), err
+	case "int64":
+		return strconv.ParseInt(val, 0, 64)
+	default:
+		panic("unreachable")
+	}
+}
+
+// parseUint returns an unsigned integer of value val and type typ.
+func parseUint(val, typ string) (any, error) {
+	switch typ {
+	case "uint":
+		i, err := strconv.ParseUint(val, 0, 64)
+		return uint(i), err
+	case "uint8", "byte":
+		i, err := strconv.ParseUint(val, 0, 8)
+		return uint8(i), err
+	case "uint16":
+		i, err := strconv.ParseUint(val, 0, 16)
+		return uint16(i), err
+	case "uint32":
+		i, err := strconv.ParseUint(val, 0, 32)
+		return uint32(i), err
+	case "uint64":
+		return strconv.ParseUint(val, 0, 64)
+	default:
+		panic("unreachable")
+	}
+}
diff --git a/contrib/go/_std_1.20/src/internal/fuzz/fuzz.go b/contrib/go/_std_1.20/src/internal/fuzz/fuzz.go
new file mode 100644
index 0000000000..7d4fe06198
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/fuzz/fuzz.go
@@ -0,0 +1,1083 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package fuzz provides common fuzzing functionality for tests built with
+// "go test" and for programs that use fuzzing functionality in the testing
+// package.
+package fuzz
+
+import (
+	"bytes"
+	"context"
+	"crypto/sha256"
+	"errors"
+	"fmt"
+	"internal/godebug"
+	"io"
+	"math/bits"
+	"os"
+	"path/filepath"
+	"reflect"
+	"runtime"
+	"strings"
+	"time"
+)
+
+// CoordinateFuzzingOpts is a set of arguments for CoordinateFuzzing.
+// The zero value is valid for each field unless specified otherwise.
+type CoordinateFuzzingOpts struct {
+	// Log is a writer for logging progress messages and warnings.
+	// If nil, io.Discard will be used instead.
+	Log io.Writer
+
+	// Timeout is the amount of wall clock time to spend fuzzing after the corpus
+	// has loaded. If zero, there will be no time limit.
+	Timeout time.Duration
+
+	// Limit is the number of random values to generate and test. If zero,
+	// there will be no limit on the number of generated values.
+	Limit int64
+
+	// MinimizeTimeout is the amount of wall clock time to spend minimizing
+	// after discovering a crasher. If zero, there will be no time limit. If
+	// MinimizeTimeout and MinimizeLimit are both zero, then minimization will
+	// be disabled.
+	MinimizeTimeout time.Duration
+
+	// MinimizeLimit is the maximum number of calls to the fuzz function to be
+	// made while minimizing after finding a crash. If zero, there will be no
+	// limit. Calls to the fuzz function made when minimizing also count toward
+	// Limit. If MinimizeTimeout and MinimizeLimit are both zero, then
+	// minimization will be disabled.
+	MinimizeLimit int64
+
+	// parallel is the number of worker processes to run in parallel. If zero,
+	// CoordinateFuzzing will run GOMAXPROCS workers.
+	Parallel int
+
+	// Seed is a list of seed values added by the fuzz target with testing.F.Add
+	// and in testdata.
+	Seed []CorpusEntry
+
+	// Types is the list of types which make up a corpus entry.
+	// Types must be set and must match values in Seed.
+	Types []reflect.Type
+
+	// CorpusDir is a directory where files containing values that crash the
+	// code being tested may be written. CorpusDir must be set.
+	CorpusDir string
+
+	// CacheDir is a directory containing additional "interesting" values.
+	// The fuzzer may derive new values from these, and may write new values here.
+	CacheDir string
+}
+
+// CoordinateFuzzing creates several worker processes and communicates with
+// them to test random inputs that could trigger crashes and expose bugs.
+// The worker processes run the same binary in the same directory with the
+// same environment variables as the coordinator process. Workers also run
+// with the same arguments as the coordinator, except with the -test.fuzzworker
+// flag prepended to the argument list.
+//
+// If a crash occurs, the function will return an error containing information
+// about the crash, which can be reported to the user.
+func CoordinateFuzzing(ctx context.Context, opts CoordinateFuzzingOpts) (err error) {
+	if err := ctx.Err(); err != nil {
+		return err
+	}
+	if opts.Log == nil {
+		opts.Log = io.Discard
+	}
+	if opts.Parallel == 0 {
+		opts.Parallel = runtime.GOMAXPROCS(0)
+	}
+	if opts.Limit > 0 && int64(opts.Parallel) > opts.Limit {
+		// Don't start more workers than we need.
+		opts.Parallel = int(opts.Limit)
+	}
+
+	c, err := newCoordinator(opts)
+	if err != nil {
+		return err
+	}
+
+	if opts.Timeout > 0 {
+		var cancel func()
+		ctx, cancel = context.WithTimeout(ctx, opts.Timeout)
+		defer cancel()
+	}
+
+	// fuzzCtx is used to stop workers, for example, after finding a crasher.
+	fuzzCtx, cancelWorkers := context.WithCancel(ctx)
+	defer cancelWorkers()
+	doneC := ctx.Done()
+
+	// stop is called when a worker encounters a fatal error.
+	var fuzzErr error
+	stopping := false
+	stop := func(err error) {
+		if err == fuzzCtx.Err() || isInterruptError(err) {
+			// Suppress cancellation errors and terminations due to SIGINT.
+			// The messages are not helpful since either the user triggered the error
+			// (with ^C) or another more helpful message will be printed (a crasher).
+			err = nil
+		}
+		if err != nil && (fuzzErr == nil || fuzzErr == ctx.Err()) {
+			fuzzErr = err
+		}
+		if stopping {
+			return
+		}
+		stopping = true
+		cancelWorkers()
+		doneC = nil
+	}
+
+	// Ensure that any crash we find is written to the corpus, even if an error
+	// or interruption occurs while minimizing it.
+	crashWritten := false
+	defer func() {
+		if c.crashMinimizing == nil || crashWritten {
+			return
+		}
+		werr := writeToCorpus(&c.crashMinimizing.entry, opts.CorpusDir)
+		if werr != nil {
+			err = fmt.Errorf("%w\n%v", err, werr)
+			return
+		}
+		if err == nil {
+			err = &crashError{
+				path: c.crashMinimizing.entry.Path,
+				err:  errors.New(c.crashMinimizing.crasherMsg),
+			}
+		}
+	}()
+
+	// Start workers.
+	// TODO(jayconrod): do we want to support fuzzing different binaries?
+	dir := "" // same as self
+	binPath := os.Args[0]
+	args := append([]string{"-test.fuzzworker"}, os.Args[1:]...)
+	env := os.Environ() // same as self
+
+	errC := make(chan error)
+	workers := make([]*worker, opts.Parallel)
+	for i := range workers {
+		var err error
+		workers[i], err = newWorker(c, dir, binPath, args, env)
+		if err != nil {
+			return err
+		}
+	}
+	for i := range workers {
+		w := workers[i]
+		go func() {
+			err := w.coordinate(fuzzCtx)
+			if fuzzCtx.Err() != nil || isInterruptError(err) {
+				err = nil
+			}
+			cleanErr := w.cleanup()
+			if err == nil {
+				err = cleanErr
+			}
+			errC <- err
+		}()
+	}
+
+	// Main event loop.
+	// Do not return until all workers have terminated. We avoid a deadlock by
+	// receiving messages from workers even after ctx is cancelled.
+	activeWorkers := len(workers)
+	statTicker := time.NewTicker(3 * time.Second)
+	defer statTicker.Stop()
+	defer c.logStats()
+
+	c.logStats()
+	for {
+		var inputC chan fuzzInput
+		input, ok := c.peekInput()
+		if ok && c.crashMinimizing == nil && !stopping {
+			inputC = c.inputC
+		}
+
+		var minimizeC chan fuzzMinimizeInput
+		minimizeInput, ok := c.peekMinimizeInput()
+		if ok && !stopping {
+			minimizeC = c.minimizeC
+		}
+
+		select {
+		case <-doneC:
+			// Interrupted, cancelled, or timed out.
+			// stop sets doneC to nil so we don't busy wait here.
+			stop(ctx.Err())
+
+		case err := <-errC:
+			// A worker terminated, possibly after encountering a fatal error.
+			stop(err)
+			activeWorkers--
+			if activeWorkers == 0 {
+				return fuzzErr
+			}
+
+		case result := <-c.resultC:
+			// Received response from worker.
+			if stopping {
+				break
+			}
+			c.updateStats(result)
+
+			if result.crasherMsg != "" {
+				if c.warmupRun() && result.entry.IsSeed {
+					target := filepath.Base(c.opts.CorpusDir)
+					fmt.Fprintf(c.opts.Log, "failure while testing seed corpus entry: %s/%s\n", target, testName(result.entry.Parent))
+					stop(errors.New(result.crasherMsg))
+					break
+				}
+				if c.canMinimize() && result.canMinimize {
+					if c.crashMinimizing != nil {
+						// This crash is not minimized, and another crash is being minimized.
+						// Ignore this one and wait for the other one to finish.
+						break
+					}
+					// Found a crasher but haven't yet attempted to minimize it.
+					// Send it back to a worker for minimization. Disable inputC so
+					// other workers don't continue fuzzing.
+					c.crashMinimizing = &result
+					fmt.Fprintf(c.opts.Log, "fuzz: minimizing %d-byte failing input file\n", len(result.entry.Data))
+					c.queueForMinimization(result, nil)
+				} else if !crashWritten {
+					// Found a crasher that's either minimized or not minimizable.
+					// Write to corpus and stop.
+					err := writeToCorpus(&result.entry, opts.CorpusDir)
+					if err == nil {
+						crashWritten = true
+						err = &crashError{
+							path: result.entry.Path,
+							err:  errors.New(result.crasherMsg),
+						}
+					}
+					if shouldPrintDebugInfo() {
+						fmt.Fprintf(
+							c.opts.Log,
+							"DEBUG new crasher, elapsed: %s, id: %s, parent: %s, gen: %d, size: %d, exec time: %s\n",
+							c.elapsed(),
+							result.entry.Path,
+							result.entry.Parent,
+							result.entry.Generation,
+							len(result.entry.Data),
+							result.entryDuration,
+						)
+					}
+					stop(err)
+				}
+			} else if result.coverageData != nil {
+				if c.warmupRun() {
+					if shouldPrintDebugInfo() {
+						fmt.Fprintf(
+							c.opts.Log,
+							"DEBUG processed an initial input, elapsed: %s, id: %s, new bits: %d, size: %d, exec time: %s\n",
+							c.elapsed(),
+							result.entry.Parent,
+							countBits(diffCoverage(c.coverageMask, result.coverageData)),
+							len(result.entry.Data),
+							result.entryDuration,
+						)
+					}
+					c.updateCoverage(result.coverageData)
+					c.warmupInputLeft--
+					if c.warmupInputLeft == 0 {
+						fmt.Fprintf(c.opts.Log, "fuzz: elapsed: %s, gathering baseline coverage: %d/%d completed, now fuzzing with %d workers\n", c.elapsed(), c.warmupInputCount, c.warmupInputCount, c.opts.Parallel)
+						if shouldPrintDebugInfo() {
+							fmt.Fprintf(
+								c.opts.Log,
+								"DEBUG finished processing input corpus, elapsed: %s, entries: %d, initial coverage bits: %d\n",
+								c.elapsed(),
+								len(c.corpus.entries),
+								countBits(c.coverageMask),
+							)
+						}
+					}
+				} else if keepCoverage := diffCoverage(c.coverageMask, result.coverageData); keepCoverage != nil {
+					// Found a value that expanded coverage.
+					// It's not a crasher, but we may want to add it to the on-disk
+					// corpus and prioritize it for future fuzzing.
+					// TODO(jayconrod, katiehockman): Prioritize fuzzing these
+					// values which expanded coverage, perhaps based on the
+					// number of new edges that this result expanded.
+					// TODO(jayconrod, katiehockman): Don't write a value that's already
+					// in the corpus.
+					if c.canMinimize() && result.canMinimize && c.crashMinimizing == nil {
+						// Send back to workers to find a smaller value that preserves
+						// at least one new coverage bit.
+						c.queueForMinimization(result, keepCoverage)
+					} else {
+						// Update the coordinator's coverage mask and save the value.
+						inputSize := len(result.entry.Data)
+						entryNew, err := c.addCorpusEntries(true, result.entry)
+						if err != nil {
+							stop(err)
+							break
+						}
+						if !entryNew {
+							continue
+						}
+						c.updateCoverage(keepCoverage)
+						c.inputQueue.enqueue(result.entry)
+						c.interestingCount++
+						if shouldPrintDebugInfo() {
+							fmt.Fprintf(
+								c.opts.Log,
+								"DEBUG new interesting input, elapsed: %s, id: %s, parent: %s, gen: %d, new bits: %d, total bits: %d, size: %d, exec time: %s\n",
+								c.elapsed(),
+								result.entry.Path,
+								result.entry.Parent,
+								result.entry.Generation,
+								countBits(keepCoverage),
+								countBits(c.coverageMask),
+								inputSize,
+								result.entryDuration,
+							)
+						}
+					}
+				} else {
+					if shouldPrintDebugInfo() {
+						fmt.Fprintf(
+							c.opts.Log,
+							"DEBUG worker reported interesting input that doesn't expand coverage, elapsed: %s, id: %s, parent: %s, canMinimize: %t\n",
+							c.elapsed(),
+							result.entry.Path,
+							result.entry.Parent,
+							result.canMinimize,
+						)
+					}
+				}
+			} else if c.warmupRun() {
+				// No error or coverage data was reported for this input during
+				// warmup, so continue processing results.
+				c.warmupInputLeft--
+				if c.warmupInputLeft == 0 {
+					fmt.Fprintf(c.opts.Log, "fuzz: elapsed: %s, testing seed corpus: %d/%d completed, now fuzzing with %d workers\n", c.elapsed(), c.warmupInputCount, c.warmupInputCount, c.opts.Parallel)
+					if shouldPrintDebugInfo() {
+						fmt.Fprintf(
+							c.opts.Log,
+							"DEBUG finished testing-only phase, elapsed: %s, entries: %d\n",
+							time.Since(c.startTime),
+							len(c.corpus.entries),
+						)
+					}
+				}
+			}
+
+			// Once the result has been processed, stop the worker if we
+			// have reached the fuzzing limit.
+			if c.opts.Limit > 0 && c.count >= c.opts.Limit {
+				stop(nil)
+			}
+
+		case inputC <- input:
+			// Sent the next input to a worker.
+			c.sentInput(input)
+
+		case minimizeC <- minimizeInput:
+			// Sent the next input for minimization to a worker.
+			c.sentMinimizeInput(minimizeInput)
+
+		case <-statTicker.C:
+			c.logStats()
+		}
+	}
+
+	// TODO(jayconrod,katiehockman): if a crasher can't be written to the corpus,
+	// write to the cache instead.
+}
+
+// crashError wraps a crasher written to the seed corpus. It saves the name
+// of the file where the input causing the crasher was saved. The testing
+// framework uses this to report a command to re-run that specific input.
+type crashError struct {
+	path string
+	err  error
+}
+
+func (e *crashError) Error() string {
+	return e.err.Error()
+}
+
+func (e *crashError) Unwrap() error {
+	return e.err
+}
+
+func (e *crashError) CrashPath() string {
+	return e.path
+}
+
+type corpus struct {
+	entries []CorpusEntry
+	hashes  map[[sha256.Size]byte]bool
+}
+
+// addCorpusEntries adds entries to the corpus, and optionally writes the entries
+// to the cache directory. If an entry is already in the corpus it is skipped. If
+// all of the entries are unique, addCorpusEntries returns true and a nil error,
+// if at least one of the entries was a duplicate, it returns false and a nil error.
+func (c *coordinator) addCorpusEntries(addToCache bool, entries ...CorpusEntry) (bool, error) {
+	noDupes := true
+	for _, e := range entries {
+		data, err := corpusEntryData(e)
+		if err != nil {
+			return false, err
+		}
+		h := sha256.Sum256(data)
+		if c.corpus.hashes[h] {
+			noDupes = false
+			continue
+		}
+		if addToCache {
+			if err := writeToCorpus(&e, c.opts.CacheDir); err != nil {
+				return false, err
+			}
+			// For entries written to disk, we don't hold onto the bytes,
+			// since the corpus would consume a significant amount of
+			// memory.
+			e.Data = nil
+		}
+		c.corpus.hashes[h] = true
+		c.corpus.entries = append(c.corpus.entries, e)
+	}
+	return noDupes, nil
+}
+
+// CorpusEntry represents an individual input for fuzzing.
+//
+// We must use an equivalent type in the testing and testing/internal/testdeps
+// packages, but testing can't import this package directly, and we don't want
+// to export this type from testing. Instead, we use the same struct type and
+// use a type alias (not a defined type) for convenience.
+type CorpusEntry = struct {
+	Parent string
+
+	// Path is the path of the corpus file, if the entry was loaded from disk.
+	// For other entries, including seed values provided by f.Add, Path is the
+	// name of the test, e.g. seed#0 or its hash.
+	Path string
+
+	// Data is the raw input data. Data should only be populated for seed
+	// values. For on-disk corpus files, Data will be nil, as it will be loaded
+	// from disk using Path.
+	Data []byte
+
+	// Values is the unmarshaled values from a corpus file.
+	Values []any
+
+	Generation int
+
+	// IsSeed indicates whether this entry is part of the seed corpus.
+	IsSeed bool
+}
+
+// corpusEntryData returns the raw input bytes, either from the data struct
+// field, or from disk.
+func corpusEntryData(ce CorpusEntry) ([]byte, error) {
+	if ce.Data != nil {
+		return ce.Data, nil
+	}
+
+	return os.ReadFile(ce.Path)
+}
+
+type fuzzInput struct {
+	// entry is the value to test initially. The worker will randomly mutate
+	// values from this starting point.
+	entry CorpusEntry
+
+	// timeout is the time to spend fuzzing variations of this input,
+	// not including starting or cleaning up.
+	timeout time.Duration
+
+	// limit is the maximum number of calls to the fuzz function the worker may
+	// make. The worker may make fewer calls, for example, if it finds an
+	// error early. If limit is zero, there is no limit on calls to the
+	// fuzz function.
+	limit int64
+
+	// warmup indicates whether this is a warmup input before fuzzing begins. If
+	// true, the input should not be fuzzed.
+	warmup bool
+
+	// coverageData reflects the coordinator's current coverageMask.
+	coverageData []byte
+}
+
+type fuzzResult struct {
+	// entry is an interesting value or a crasher.
+	entry CorpusEntry
+
+	// crasherMsg is an error message from a crash. It's "" if no crash was found.
+	crasherMsg string
+
+	// canMinimize is true if the worker should attempt to minimize this result.
+	// It may be false because an attempt has already been made.
+	canMinimize bool
+
+	// coverageData is set if the worker found new coverage.
+	coverageData []byte
+
+	// limit is the number of values the coordinator asked the worker
+	// to test. 0 if there was no limit.
+	limit int64
+
+	// count is the number of values the worker actually tested.
+	count int64
+
+	// totalDuration is the time the worker spent testing inputs.
+	totalDuration time.Duration
+
+	// entryDuration is the time the worker spent execution an interesting result
+	entryDuration time.Duration
+}
+
+type fuzzMinimizeInput struct {
+	// entry is an interesting value or crasher to minimize.
+	entry CorpusEntry
+
+	// crasherMsg is an error message from a crash. It's "" if no crash was found.
+	// If set, the worker will attempt to find a smaller input that also produces
+	// an error, though not necessarily the same error.
+	crasherMsg string
+
+	// limit is the maximum number of calls to the fuzz function the worker may
+	// make. The worker may make fewer calls, for example, if it can't reproduce
+	// an error. If limit is zero, there is no limit on calls to the fuzz function.
+	limit int64
+
+	// timeout is the time to spend minimizing this input.
+	// A zero timeout means no limit.
+	timeout time.Duration
+
+	// keepCoverage is a set of coverage bits that entry found that were not in
+	// the coordinator's combined set. When minimizing, the worker should find an
+	// input that preserves at least one of these bits. keepCoverage is nil for
+	// crashing inputs.
+	keepCoverage []byte
+}
+
+// coordinator holds channels that workers can use to communicate with
+// the coordinator.
+type coordinator struct {
+	opts CoordinateFuzzingOpts
+
+	// startTime is the time we started the workers after loading the corpus.
+	// Used for logging.
+	startTime time.Time
+
+	// inputC is sent values to fuzz by the coordinator. Any worker may receive
+	// values from this channel. Workers send results to resultC.
+	inputC chan fuzzInput
+
+	// minimizeC is sent values to minimize by the coordinator. Any worker may
+	// receive values from this channel. Workers send results to resultC.
+	minimizeC chan fuzzMinimizeInput
+
+	// resultC is sent results of fuzzing by workers. The coordinator
+	// receives these. Multiple types of messages are allowed.
+	resultC chan fuzzResult
+
+	// count is the number of values fuzzed so far.
+	count int64
+
+	// countLastLog is the number of values fuzzed when the output was last
+	// logged.
+	countLastLog int64
+
+	// timeLastLog is the time at which the output was last logged.
+	timeLastLog time.Time
+
+	// interestingCount is the number of unique interesting values which have
+	// been found this execution.
+	interestingCount int
+
+	// warmupInputCount is the count of all entries in the corpus which will
+	// need to be received from workers to run once during warmup, but not fuzz.
+	// This could be for coverage data, or only for the purposes of verifying
+	// that the seed corpus doesn't have any crashers. See warmupRun.
+	warmupInputCount int
+
+	// warmupInputLeft is the number of entries in the corpus which still need
+	// to be received from workers to run once during warmup, but not fuzz.
+	// See warmupInputLeft.
+	warmupInputLeft int
+
+	// duration is the time spent fuzzing inside workers, not counting time
+	// starting up or tearing down.
+	duration time.Duration
+
+	// countWaiting is the number of fuzzing executions the coordinator is
+	// waiting on workers to complete.
+	countWaiting int64
+
+	// corpus is a set of interesting values, including the seed corpus and
+	// generated values that workers reported as interesting.
+	corpus corpus
+
+	// minimizationAllowed is true if one or more of the types of fuzz
+	// function's parameters can be minimized.
+	minimizationAllowed bool
+
+	// inputQueue is a queue of inputs that workers should try fuzzing. This is
+	// initially populated from the seed corpus and cached inputs. More inputs
+	// may be added as new coverage is discovered.
+	inputQueue queue
+
+	// minimizeQueue is a queue of inputs that caused errors or exposed new
+	// coverage. Workers should attempt to find smaller inputs that do the
+	// same thing.
+	minimizeQueue queue
+
+	// crashMinimizing is the crash that is currently being minimized.
+	crashMinimizing *fuzzResult
+
+	// coverageMask aggregates coverage that was found for all inputs in the
+	// corpus. Each byte represents a single basic execution block. Each set bit
+	// within the byte indicates that an input has triggered that block at least
+	// 1 << n times, where n is the position of the bit in the byte. For example, a
+	// value of 12 indicates that separate inputs have triggered this block
+	// between 4-7 times and 8-15 times.
+	coverageMask []byte
+}
+
+func newCoordinator(opts CoordinateFuzzingOpts) (*coordinator, error) {
+	// Make sure all of the seed corpus has marshalled data.
+	for i := range opts.Seed {
+		if opts.Seed[i].Data == nil && opts.Seed[i].Values != nil {
+			opts.Seed[i].Data = marshalCorpusFile(opts.Seed[i].Values...)
+		}
+	}
+	c := &coordinator{
+		opts:        opts,
+		startTime:   time.Now(),
+		inputC:      make(chan fuzzInput),
+		minimizeC:   make(chan fuzzMinimizeInput),
+		resultC:     make(chan fuzzResult),
+		timeLastLog: time.Now(),
+		corpus:      corpus{hashes: make(map[[sha256.Size]byte]bool)},
+	}
+	if err := c.readCache(); err != nil {
+		return nil, err
+	}
+	if opts.MinimizeLimit > 0 || opts.MinimizeTimeout > 0 {
+		for _, t := range opts.Types {
+			if isMinimizable(t) {
+				c.minimizationAllowed = true
+				break
+			}
+		}
+	}
+
+	covSize := len(coverage())
+	if covSize == 0 {
+		fmt.Fprintf(c.opts.Log, "warning: the test binary was not built with coverage instrumentation, so fuzzing will run without coverage guidance and may be inefficient\n")
+		// Even though a coverage-only run won't occur, we should still run all
+		// of the seed corpus to make sure there are no existing failures before
+		// we start fuzzing.
+		c.warmupInputCount = len(c.opts.Seed)
+		for _, e := range c.opts.Seed {
+			c.inputQueue.enqueue(e)
+		}
+	} else {
+		c.warmupInputCount = len(c.corpus.entries)
+		for _, e := range c.corpus.entries {
+			c.inputQueue.enqueue(e)
+		}
+		// Set c.coverageMask to a clean []byte full of zeros.
+		c.coverageMask = make([]byte, covSize)
+	}
+	c.warmupInputLeft = c.warmupInputCount
+
+	if len(c.corpus.entries) == 0 {
+		fmt.Fprintf(c.opts.Log, "warning: starting with empty corpus\n")
+		var vals []any
+		for _, t := range opts.Types {
+			vals = append(vals, zeroValue(t))
+		}
+		data := marshalCorpusFile(vals...)
+		h := sha256.Sum256(data)
+		name := fmt.Sprintf("%x", h[:4])
+		c.addCorpusEntries(false, CorpusEntry{Path: name, Data: data})
+	}
+
+	return c, nil
+}
+
+func (c *coordinator) updateStats(result fuzzResult) {
+	c.count += result.count
+	c.countWaiting -= result.limit
+	c.duration += result.totalDuration
+}
+
+func (c *coordinator) logStats() {
+	now := time.Now()
+	if c.warmupRun() {
+		runSoFar := c.warmupInputCount - c.warmupInputLeft
+		if coverageEnabled {
+			fmt.Fprintf(c.opts.Log, "fuzz: elapsed: %s, gathering baseline coverage: %d/%d completed\n", c.elapsed(), runSoFar, c.warmupInputCount)
+		} else {
+			fmt.Fprintf(c.opts.Log, "fuzz: elapsed: %s, testing seed corpus: %d/%d completed\n", c.elapsed(), runSoFar, c.warmupInputCount)
+		}
+	} else if c.crashMinimizing != nil {
+		fmt.Fprintf(c.opts.Log, "fuzz: elapsed: %s, minimizing\n", c.elapsed())
+	} else {
+		rate := float64(c.count-c.countLastLog) / now.Sub(c.timeLastLog).Seconds()
+		if coverageEnabled {
+			total := c.warmupInputCount + c.interestingCount
+			fmt.Fprintf(c.opts.Log, "fuzz: elapsed: %s, execs: %d (%.0f/sec), new interesting: %d (total: %d)\n", c.elapsed(), c.count, rate, c.interestingCount, total)
+		} else {
+			fmt.Fprintf(c.opts.Log, "fuzz: elapsed: %s, execs: %d (%.0f/sec)\n", c.elapsed(), c.count, rate)
+		}
+	}
+	c.countLastLog = c.count
+	c.timeLastLog = now
+}
+
+// peekInput returns the next value that should be sent to workers.
+// If the number of executions is limited, the returned value includes
+// a limit for one worker. If there are no executions left, peekInput returns
+// a zero value and false.
+//
+// peekInput doesn't actually remove the input from the queue. The caller
+// must call sentInput after sending the input.
+//
+// If the input queue is empty and the coverage/testing-only run has completed,
+// queue refills it from the corpus.
+func (c *coordinator) peekInput() (fuzzInput, bool) {
+	if c.opts.Limit > 0 && c.count+c.countWaiting >= c.opts.Limit {
+		// Already making the maximum number of calls to the fuzz function.
+		// Don't send more inputs right now.
+		return fuzzInput{}, false
+	}
+	if c.inputQueue.len == 0 {
+		if c.warmupRun() {
+			// Wait for coverage/testing-only run to finish before sending more
+			// inputs.
+			return fuzzInput{}, false
+		}
+		c.refillInputQueue()
+	}
+
+	entry, ok := c.inputQueue.peek()
+	if !ok {
+		panic("input queue empty after refill")
+	}
+	input := fuzzInput{
+		entry:   entry.(CorpusEntry),
+		timeout: workerFuzzDuration,
+		warmup:  c.warmupRun(),
+	}
+	if c.coverageMask != nil {
+		input.coverageData = bytes.Clone(c.coverageMask)
+	}
+	if input.warmup {
+		// No fuzzing will occur, but it should count toward the limit set by
+		// -fuzztime.
+		input.limit = 1
+		return input, true
+	}
+
+	if c.opts.Limit > 0 {
+		input.limit = c.opts.Limit / int64(c.opts.Parallel)
+		if c.opts.Limit%int64(c.opts.Parallel) > 0 {
+			input.limit++
+		}
+		remaining := c.opts.Limit - c.count - c.countWaiting
+		if input.limit > remaining {
+			input.limit = remaining
+		}
+	}
+	return input, true
+}
+
+// sentInput updates internal counters after an input is sent to c.inputC.
+func (c *coordinator) sentInput(input fuzzInput) {
+	c.inputQueue.dequeue()
+	c.countWaiting += input.limit
+}
+
+// refillInputQueue refills the input queue from the corpus after it becomes
+// empty.
+func (c *coordinator) refillInputQueue() {
+	for _, e := range c.corpus.entries {
+		c.inputQueue.enqueue(e)
+	}
+}
+
+// queueForMinimization creates a fuzzMinimizeInput from result and adds it
+// to the minimization queue to be sent to workers.
+func (c *coordinator) queueForMinimization(result fuzzResult, keepCoverage []byte) {
+	if result.crasherMsg != "" {
+		c.minimizeQueue.clear()
+	}
+
+	input := fuzzMinimizeInput{
+		entry:        result.entry,
+		crasherMsg:   result.crasherMsg,
+		keepCoverage: keepCoverage,
+	}
+	c.minimizeQueue.enqueue(input)
+}
+
+// peekMinimizeInput returns the next input that should be sent to workers for
+// minimization.
+func (c *coordinator) peekMinimizeInput() (fuzzMinimizeInput, bool) {
+	if !c.canMinimize() {
+		// Already making the maximum number of calls to the fuzz function.
+		// Don't send more inputs right now.
+		return fuzzMinimizeInput{}, false
+	}
+	v, ok := c.minimizeQueue.peek()
+	if !ok {
+		return fuzzMinimizeInput{}, false
+	}
+	input := v.(fuzzMinimizeInput)
+
+	if c.opts.MinimizeTimeout > 0 {
+		input.timeout = c.opts.MinimizeTimeout
+	}
+	if c.opts.MinimizeLimit > 0 {
+		input.limit = c.opts.MinimizeLimit
+	} else if c.opts.Limit > 0 {
+		if input.crasherMsg != "" {
+			input.limit = c.opts.Limit
+		} else {
+			input.limit = c.opts.Limit / int64(c.opts.Parallel)
+			if c.opts.Limit%int64(c.opts.Parallel) > 0 {
+				input.limit++
+			}
+		}
+	}
+	if c.opts.Limit > 0 {
+		remaining := c.opts.Limit - c.count - c.countWaiting
+		if input.limit > remaining {
+			input.limit = remaining
+		}
+	}
+	return input, true
+}
+
+// sentMinimizeInput removes an input from the minimization queue after it's
+// sent to minimizeC.
+func (c *coordinator) sentMinimizeInput(input fuzzMinimizeInput) {
+	c.minimizeQueue.dequeue()
+	c.countWaiting += input.limit
+}
+
+// warmupRun returns true while the coordinator is running inputs without
+// mutating them as a warmup before fuzzing. This could be to gather baseline
+// coverage data for entries in the corpus, or to test all of the seed corpus
+// for errors before fuzzing begins.
+//
+// The coordinator doesn't store coverage data in the cache with each input
+// because that data would be invalid when counter offsets in the test binary
+// change.
+//
+// When gathering coverage, the coordinator sends each entry to a worker to
+// gather coverage for that entry only, without fuzzing or minimizing. This
+// phase ends when all workers have finished, and the coordinator has a combined
+// coverage map.
+func (c *coordinator) warmupRun() bool {
+	return c.warmupInputLeft > 0
+}
+
+// updateCoverage sets bits in c.coverageMask that are set in newCoverage.
+// updateCoverage returns the number of newly set bits. See the comment on
+// coverageMask for the format.
+func (c *coordinator) updateCoverage(newCoverage []byte) int {
+	if len(newCoverage) != len(c.coverageMask) {
+		panic(fmt.Sprintf("number of coverage counters changed at runtime: %d, expected %d", len(newCoverage), len(c.coverageMask)))
+	}
+	newBitCount := 0
+	for i := range newCoverage {
+		diff := newCoverage[i] &^ c.coverageMask[i]
+		newBitCount += bits.OnesCount8(diff)
+		c.coverageMask[i] |= newCoverage[i]
+	}
+	return newBitCount
+}
+
+// canMinimize returns whether the coordinator should attempt to find smaller
+// inputs that reproduce a crash or new coverage.
+func (c *coordinator) canMinimize() bool {
+	return c.minimizationAllowed &&
+		(c.opts.Limit == 0 || c.count+c.countWaiting < c.opts.Limit)
+}
+
+func (c *coordinator) elapsed() time.Duration {
+	return time.Since(c.startTime).Round(1 * time.Second)
+}
+
+// readCache creates a combined corpus from seed values and values in the cache
+// (in GOCACHE/fuzz).
+//
+// TODO(fuzzing): need a mechanism that can remove values that
+// aren't useful anymore, for example, because they have the wrong type.
+func (c *coordinator) readCache() error {
+	if _, err := c.addCorpusEntries(false, c.opts.Seed...); err != nil {
+		return err
+	}
+	entries, err := ReadCorpus(c.opts.CacheDir, c.opts.Types)
+	if err != nil {
+		if _, ok := err.(*MalformedCorpusError); !ok {
+			// It's okay if some files in the cache directory are malformed and
+			// are not included in the corpus, but fail if it's an I/O error.
+			return err
+		}
+		// TODO(jayconrod,katiehockman): consider printing some kind of warning
+		// indicating the number of files which were skipped because they are
+		// malformed.
+	}
+	if _, err := c.addCorpusEntries(false, entries...); err != nil {
+		return err
+	}
+	return nil
+}
+
+// MalformedCorpusError is an error found while reading the corpus from the
+// filesystem. All of the errors are stored in the errs list. The testing
+// framework uses this to report malformed files in testdata.
+type MalformedCorpusError struct {
+	errs []error
+}
+
+func (e *MalformedCorpusError) Error() string {
+	var msgs []string
+	for _, s := range e.errs {
+		msgs = append(msgs, s.Error())
+	}
+	return strings.Join(msgs, "\n")
+}
+
+// ReadCorpus reads the corpus from the provided dir. The returned corpus
+// entries are guaranteed to match the given types. Any malformed files will
+// be saved in a MalformedCorpusError and returned, along with the most recent
+// error.
+func ReadCorpus(dir string, types []reflect.Type) ([]CorpusEntry, error) {
+	files, err := os.ReadDir(dir)
+	if os.IsNotExist(err) {
+		return nil, nil // No corpus to read
+	} else if err != nil {
+		return nil, fmt.Errorf("reading seed corpus from testdata: %v", err)
+	}
+	var corpus []CorpusEntry
+	var errs []error
+	for _, file := range files {
+		// TODO(jayconrod,katiehockman): determine when a file is a fuzzing input
+		// based on its name. We should only read files created by writeToCorpus.
+		// If we read ALL files, we won't be able to change the file format by
+		// changing the extension. We also won't be able to add files like
+		// README.txt explaining why the directory exists.
+		if file.IsDir() {
+			continue
+		}
+		filename := filepath.Join(dir, file.Name())
+		data, err := os.ReadFile(filename)
+		if err != nil {
+			return nil, fmt.Errorf("failed to read corpus file: %v", err)
+		}
+		var vals []any
+		vals, err = readCorpusData(data, types)
+		if err != nil {
+			errs = append(errs, fmt.Errorf("%q: %v", filename, err))
+			continue
+		}
+		corpus = append(corpus, CorpusEntry{Path: filename, Values: vals})
+	}
+	if len(errs) > 0 {
+		return corpus, &MalformedCorpusError{errs: errs}
+	}
+	return corpus, nil
+}
+
+func readCorpusData(data []byte, types []reflect.Type) ([]any, error) {
+	vals, err := unmarshalCorpusFile(data)
+	if err != nil {
+		return nil, fmt.Errorf("unmarshal: %v", err)
+	}
+	if err = CheckCorpus(vals, types); err != nil {
+		return nil, err
+	}
+	return vals, nil
+}
+
+// CheckCorpus verifies that the types in vals match the expected types
+// provided.
+func CheckCorpus(vals []any, types []reflect.Type) error {
+	if len(vals) != len(types) {
+		return fmt.Errorf("wrong number of values in corpus entry: %d, want %d", len(vals), len(types))
+	}
+	valsT := make([]reflect.Type, len(vals))
+	for valsI, v := range vals {
+		valsT[valsI] = reflect.TypeOf(v)
+	}
+	for i := range types {
+		if valsT[i] != types[i] {
+			return fmt.Errorf("mismatched types in corpus entry: %v, want %v", valsT, types)
+		}
+	}
+	return nil
+}
+
+// writeToCorpus atomically writes the given bytes to a new file in testdata. If
+// the directory does not exist, it will create one. If the file already exists,
+// writeToCorpus will not rewrite it. writeToCorpus sets entry.Path to the new
+// file that was just written or an error if it failed.
+func writeToCorpus(entry *CorpusEntry, dir string) (err error) {
+	sum := fmt.Sprintf("%x", sha256.Sum256(entry.Data))[:16]
+	entry.Path = filepath.Join(dir, sum)
+	if err := os.MkdirAll(dir, 0777); err != nil {
+		return err
+	}
+	if err := os.WriteFile(entry.Path, entry.Data, 0666); err != nil {
+		os.Remove(entry.Path) // remove partially written file
+		return err
+	}
+	return nil
+}
+
+func testName(path string) string {
+	return filepath.Base(path)
+}
+
+func zeroValue(t reflect.Type) any {
+	for _, v := range zeroVals {
+		if reflect.TypeOf(v) == t {
+			return v
+		}
+	}
+	panic(fmt.Sprintf("unsupported type: %v", t))
+}
+
+var zeroVals []any = []any{
+	[]byte(""),
+	string(""),
+	false,
+	byte(0),
+	rune(0),
+	float32(0),
+	float64(0),
+	int(0),
+	int8(0),
+	int16(0),
+	int32(0),
+	int64(0),
+	uint(0),
+	uint8(0),
+	uint16(0),
+	uint32(0),
+	uint64(0),
+}
+
+var debugInfo = godebug.New("fuzzdebug").Value() == "1"
+
+func shouldPrintDebugInfo() bool {
+	return debugInfo
+}
diff --git a/contrib/go/_std_1.20/src/internal/fuzz/mem.go b/contrib/go/_std_1.20/src/internal/fuzz/mem.go
new file mode 100644
index 0000000000..4155e4e83e
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/fuzz/mem.go
@@ -0,0 +1,138 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package fuzz
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"unsafe"
+)
+
+// sharedMem manages access to a region of virtual memory mapped from a file,
+// shared between multiple processes. The region includes space for a header and
+// a value of variable length.
+//
+// When fuzzing, the coordinator creates a sharedMem from a temporary file for
+// each worker. This buffer is used to pass values to fuzz between processes.
+// Care must be taken to manage access to shared memory across processes;
+// sharedMem provides no synchronization on its own. See workerComm for an
+// explanation.
+type sharedMem struct {
+	// f is the file mapped into memory.
+	f *os.File
+
+	// region is the mapped region of virtual memory for f. The content of f may
+	// be read or written through this slice.
+	region []byte
+
+	// removeOnClose is true if the file should be deleted by Close.
+	removeOnClose bool
+
+	// sys contains OS-specific information.
+	sys sharedMemSys
+}
+
+// sharedMemHeader stores metadata in shared memory.
+type sharedMemHeader struct {
+	// count is the number of times the worker has called the fuzz function.
+	// May be reset by coordinator.
+	count int64
+
+	// valueLen is the number of bytes in region which should be read.
+	valueLen int
+
+	// randState and randInc hold the state of a pseudo-random number generator.
+	randState, randInc uint64
+
+	// rawInMem is true if the region holds raw bytes, which occurs during
+	// minimization. If true after the worker fails during minimization, this
+	// indicates that an unrecoverable error occurred, and the region can be
+	// used to retrieve the raw bytes that caused the error.
+	rawInMem bool
+}
+
+// sharedMemSize returns the size needed for a shared memory buffer that can
+// contain values of the given size.
+func sharedMemSize(valueSize int) int {
+	// TODO(jayconrod): set a reasonable maximum size per platform.
+	return int(unsafe.Sizeof(sharedMemHeader{})) + valueSize
+}
+
+// sharedMemTempFile creates a new temporary file of the given size, then maps
+// it into memory. The file will be removed when the Close method is called.
+func sharedMemTempFile(size int) (m *sharedMem, err error) {
+	// Create a temporary file.
+	f, err := os.CreateTemp("", "fuzz-*")
+	if err != nil {
+		return nil, err
+	}
+	defer func() {
+		if err != nil {
+			f.Close()
+			os.Remove(f.Name())
+		}
+	}()
+
+	// Resize it to the correct size.
+	totalSize := sharedMemSize(size)
+	if err := f.Truncate(int64(totalSize)); err != nil {
+		return nil, err
+	}
+
+	// Map the file into memory.
+	removeOnClose := true
+	return sharedMemMapFile(f, totalSize, removeOnClose)
+}
+
+// header returns a pointer to metadata within the shared memory region.
+func (m *sharedMem) header() *sharedMemHeader {
+	return (*sharedMemHeader)(unsafe.Pointer(&m.region[0]))
+}
+
+// valueRef returns the value currently stored in shared memory. The returned
+// slice points to shared memory; it is not a copy.
+func (m *sharedMem) valueRef() []byte {
+	length := m.header().valueLen
+	valueOffset := int(unsafe.Sizeof(sharedMemHeader{}))
+	return m.region[valueOffset : valueOffset+length]
+}
+
+// valueCopy returns a copy of the value stored in shared memory.
+func (m *sharedMem) valueCopy() []byte {
+	ref := m.valueRef()
+	return bytes.Clone(ref)
+}
+
+// setValue copies the data in b into the shared memory buffer and sets
+// the length. len(b) must be less than or equal to the capacity of the buffer
+// (as returned by cap(m.value())).
+func (m *sharedMem) setValue(b []byte) {
+	v := m.valueRef()
+	if len(b) > cap(v) {
+		panic(fmt.Sprintf("value length %d larger than shared memory capacity %d", len(b), cap(v)))
+	}
+	m.header().valueLen = len(b)
+	copy(v[:cap(v)], b)
+}
+
+// setValueLen sets the length of the shared memory buffer returned by valueRef
+// to n, which may be at most the cap of that slice.
+//
+// Note that we can only store the length in the shared memory header. The full
+// slice header contains a pointer, which is likely only valid for one process,
+// since each process can map shared memory at a different virtual address.
+func (m *sharedMem) setValueLen(n int) {
+	v := m.valueRef()
+	if n > cap(v) {
+		panic(fmt.Sprintf("length %d larger than shared memory capacity %d", n, cap(v)))
+	}
+	m.header().valueLen = n
+}
+
+// TODO(jayconrod): add method to resize the buffer. We'll need that when the
+// mutator can increase input length. Only the coordinator will be able to
+// do it, since we'll need to send a message to the worker telling it to
+// remap the file.
diff --git a/contrib/go/_std_1.20/src/internal/fuzz/minimize.go b/contrib/go/_std_1.20/src/internal/fuzz/minimize.go
new file mode 100644
index 0000000000..0e410fb86a
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/fuzz/minimize.go
@@ -0,0 +1,95 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package fuzz
+
+import (
+	"reflect"
+)
+
+func isMinimizable(t reflect.Type) bool {
+	return t == reflect.TypeOf("") || t == reflect.TypeOf([]byte(nil))
+}
+
+func minimizeBytes(v []byte, try func([]byte) bool, shouldStop func() bool) {
+	tmp := make([]byte, len(v))
+	// If minimization was successful at any point during minimizeBytes,
+	// then the vals slice in (*workerServer).minimizeInput will point to
+	// tmp. Since tmp is altered while making new candidates, we need to
+	// make sure that it is equal to the correct value, v, before exiting
+	// this function.
+	defer copy(tmp, v)
+
+	// First, try to cut the tail.
+	for n := 1024; n != 0; n /= 2 {
+		for len(v) > n {
+			if shouldStop() {
+				return
+			}
+			candidate := v[:len(v)-n]
+			if !try(candidate) {
+				break
+			}
+			// Set v to the new value to continue iterating.
+			v = candidate
+		}
+	}
+
+	// Then, try to remove each individual byte.
+	for i := 0; i < len(v)-1; i++ {
+		if shouldStop() {
+			return
+		}
+		candidate := tmp[:len(v)-1]
+		copy(candidate[:i], v[:i])
+		copy(candidate[i:], v[i+1:])
+		if !try(candidate) {
+			continue
+		}
+		// Update v to delete the value at index i.
+		copy(v[i:], v[i+1:])
+		v = v[:len(candidate)]
+		// v[i] is now different, so decrement i to redo this iteration
+		// of the loop with the new value.
+		i--
+	}
+
+	// Then, try to remove each possible subset of bytes.
+	for i := 0; i < len(v)-1; i++ {
+		copy(tmp, v[:i])
+		for j := len(v); j > i+1; j-- {
+			if shouldStop() {
+				return
+			}
+			candidate := tmp[:len(v)-j+i]
+			copy(candidate[i:], v[j:])
+			if !try(candidate) {
+				continue
+			}
+			// Update v and reset the loop with the new length.
+			copy(v[i:], v[j:])
+			v = v[:len(candidate)]
+			j = len(v)
+		}
+	}
+
+	// Then, try to make it more simplified and human-readable by trying to replace each
+	// byte with a printable character.
+	printableChars := []byte("012789ABCXYZabcxyz !\"#$%&'()*+,.")
+	for i, b := range v {
+		if shouldStop() {
+			return
+		}
+
+		for _, pc := range printableChars {
+			v[i] = pc
+			if try(v) {
+				// Successful. Move on to the next byte in v.
+				break
+			}
+			// Unsuccessful. Revert v[i] back to original value.
+			v[i] = b
+		}
+	}
+}
diff --git a/contrib/go/_std_1.20/src/internal/fuzz/mutator.go b/contrib/go/_std_1.20/src/internal/fuzz/mutator.go
new file mode 100644
index 0000000000..bb960660ae
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/fuzz/mutator.go
@@ -0,0 +1,300 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package fuzz
+
+import (
+	"encoding/binary"
+	"fmt"
+	"math"
+	"unsafe"
+)
+
+type mutator struct {
+	r       mutatorRand
+	scratch []byte // scratch slice to avoid additional allocations
+}
+
+func newMutator() *mutator {
+	return &mutator{r: newPcgRand()}
+}
+
+func (m *mutator) rand(n int) int {
+	return m.r.intn(n)
+}
+
+func (m *mutator) randByteOrder() binary.ByteOrder {
+	if m.r.bool() {
+		return binary.LittleEndian
+	}
+	return binary.BigEndian
+}
+
+// chooseLen chooses length of range mutation in range [1,n]. It gives
+// preference to shorter ranges.
+func (m *mutator) chooseLen(n int) int {
+	switch x := m.rand(100); {
+	case x < 90:
+		return m.rand(min(8, n)) + 1
+	case x < 99:
+		return m.rand(min(32, n)) + 1
+	default:
+		return m.rand(n) + 1
+	}
+}
+
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}
+
+// mutate performs several mutations on the provided values.
+func (m *mutator) mutate(vals []any, maxBytes int) {
+	// TODO(katiehockman): pull some of these functions into helper methods and
+	// test that each case is working as expected.
+	// TODO(katiehockman): perform more types of mutations for []byte.
+
+	// maxPerVal will represent the maximum number of bytes that each value be
+	// allowed after mutating, giving an equal amount of capacity to each line.
+	// Allow a little wiggle room for the encoding.
+	maxPerVal := maxBytes/len(vals) - 100
+
+	// Pick a random value to mutate.
+	// TODO: consider mutating more than one value at a time.
+	i := m.rand(len(vals))
+	switch v := vals[i].(type) {
+	case int:
+		vals[i] = int(m.mutateInt(int64(v), maxInt))
+	case int8:
+		vals[i] = int8(m.mutateInt(int64(v), math.MaxInt8))
+	case int16:
+		vals[i] = int16(m.mutateInt(int64(v), math.MaxInt16))
+	case int64:
+		vals[i] = m.mutateInt(v, maxInt)
+	case uint:
+		vals[i] = uint(m.mutateUInt(uint64(v), maxUint))
+	case uint16:
+		vals[i] = uint16(m.mutateUInt(uint64(v), math.MaxUint16))
+	case uint32:
+		vals[i] = uint32(m.mutateUInt(uint64(v), math.MaxUint32))
+	case uint64:
+		vals[i] = m.mutateUInt(uint64(v), maxUint)
+	case float32:
+		vals[i] = float32(m.mutateFloat(float64(v), math.MaxFloat32))
+	case float64:
+		vals[i] = m.mutateFloat(v, math.MaxFloat64)
+	case bool:
+		if m.rand(2) == 1 {
+			vals[i] = !v // 50% chance of flipping the bool
+		}
+	case rune: // int32
+		vals[i] = rune(m.mutateInt(int64(v), math.MaxInt32))
+	case byte: // uint8
+		vals[i] = byte(m.mutateUInt(uint64(v), math.MaxUint8))
+	case string:
+		if len(v) > maxPerVal {
+			panic(fmt.Sprintf("cannot mutate bytes of length %d", len(v)))
+		}
+		if cap(m.scratch) < maxPerVal {
+			m.scratch = append(make([]byte, 0, maxPerVal), v...)
+		} else {
+			m.scratch = m.scratch[:len(v)]
+			copy(m.scratch, v)
+		}
+		m.mutateBytes(&m.scratch)
+		vals[i] = string(m.scratch)
+	case []byte:
+		if len(v) > maxPerVal {
+			panic(fmt.Sprintf("cannot mutate bytes of length %d", len(v)))
+		}
+		if cap(m.scratch) < maxPerVal {
+			m.scratch = append(make([]byte, 0, maxPerVal), v...)
+		} else {
+			m.scratch = m.scratch[:len(v)]
+			copy(m.scratch, v)
+		}
+		m.mutateBytes(&m.scratch)
+		vals[i] = m.scratch
+	default:
+		panic(fmt.Sprintf("type not supported for mutating: %T", vals[i]))
+	}
+}
+
+func (m *mutator) mutateInt(v, maxValue int64) int64 {
+	var max int64
+	for {
+		max = 100
+		switch m.rand(2) {
+		case 0:
+			// Add a random number
+			if v >= maxValue {
+				continue
+			}
+			if v > 0 && maxValue-v < max {
+				// Don't let v exceed maxValue
+				max = maxValue - v
+			}
+			v += int64(1 + m.rand(int(max)))
+			return v
+		case 1:
+			// Subtract a random number
+			if v <= -maxValue {
+				continue
+			}
+			if v < 0 && maxValue+v < max {
+				// Don't let v drop below -maxValue
+				max = maxValue + v
+			}
+			v -= int64(1 + m.rand(int(max)))
+			return v
+		}
+	}
+}
+
+func (m *mutator) mutateUInt(v, maxValue uint64) uint64 {
+	var max uint64
+	for {
+		max = 100
+		switch m.rand(2) {
+		case 0:
+			// Add a random number
+			if v >= maxValue {
+				continue
+			}
+			if v > 0 && maxValue-v < max {
+				// Don't let v exceed maxValue
+				max = maxValue - v
+			}
+
+			v += uint64(1 + m.rand(int(max)))
+			return v
+		case 1:
+			// Subtract a random number
+			if v <= 0 {
+				continue
+			}
+			if v < max {
+				// Don't let v drop below 0
+				max = v
+			}
+			v -= uint64(1 + m.rand(int(max)))
+			return v
+		}
+	}
+}
+
+func (m *mutator) mutateFloat(v, maxValue float64) float64 {
+	var max float64
+	for {
+		switch m.rand(4) {
+		case 0:
+			// Add a random number
+			if v >= maxValue {
+				continue
+			}
+			max = 100
+			if v > 0 && maxValue-v < max {
+				// Don't let v exceed maxValue
+				max = maxValue - v
+			}
+			v += float64(1 + m.rand(int(max)))
+			return v
+		case 1:
+			// Subtract a random number
+			if v <= -maxValue {
+				continue
+			}
+			max = 100
+			if v < 0 && maxValue+v < max {
+				// Don't let v drop below -maxValue
+				max = maxValue + v
+			}
+			v -= float64(1 + m.rand(int(max)))
+			return v
+		case 2:
+			// Multiply by a random number
+			absV := math.Abs(v)
+			if v == 0 || absV >= maxValue {
+				continue
+			}
+			max = 10
+			if maxValue/absV < max {
+				// Don't let v go beyond the minimum or maximum value
+				max = maxValue / absV
+			}
+			v *= float64(1 + m.rand(int(max)))
+			return v
+		case 3:
+			// Divide by a random number
+			if v == 0 {
+				continue
+			}
+			v /= float64(1 + m.rand(10))
+			return v
+		}
+	}
+}
+
+type byteSliceMutator func(*mutator, []byte) []byte
+
+var byteSliceMutators = []byteSliceMutator{
+	byteSliceRemoveBytes,
+	byteSliceInsertRandomBytes,
+	byteSliceDuplicateBytes,
+	byteSliceOverwriteBytes,
+	byteSliceBitFlip,
+	byteSliceXORByte,
+	byteSliceSwapByte,
+	byteSliceArithmeticUint8,
+	byteSliceArithmeticUint16,
+	byteSliceArithmeticUint32,
+	byteSliceArithmeticUint64,
+	byteSliceOverwriteInterestingUint8,
+	byteSliceOverwriteInterestingUint16,
+	byteSliceOverwriteInterestingUint32,
+	byteSliceInsertConstantBytes,
+	byteSliceOverwriteConstantBytes,
+	byteSliceShuffleBytes,
+	byteSliceSwapBytes,
+}
+
+func (m *mutator) mutateBytes(ptrB *[]byte) {
+	b := *ptrB
+	defer func() {
+		if unsafe.SliceData(*ptrB) != unsafe.SliceData(b) {
+			panic("data moved to new address")
+		}
+		*ptrB = b
+	}()
+
+	for {
+		mut := byteSliceMutators[m.rand(len(byteSliceMutators))]
+		if mutated := mut(m, b); mutated != nil {
+			b = mutated
+			return
+		}
+	}
+}
+
+var (
+	interesting8  = []int8{-128, -1, 0, 1, 16, 32, 64, 100, 127}
+	interesting16 = []int16{-32768, -129, 128, 255, 256, 512, 1000, 1024, 4096, 32767}
+	interesting32 = []int32{-2147483648, -100663046, -32769, 32768, 65535, 65536, 100663045, 2147483647}
+)
+
+const (
+	maxUint = uint64(^uint(0))
+	maxInt  = int64(maxUint >> 1)
+)
+
+func init() {
+	for _, v := range interesting8 {
+		interesting16 = append(interesting16, int16(v))
+	}
+	for _, v := range interesting16 {
+		interesting32 = append(interesting32, int32(v))
+	}
+}
diff --git a/contrib/go/_std_1.20/src/internal/fuzz/mutators_byteslice.go b/contrib/go/_std_1.20/src/internal/fuzz/mutators_byteslice.go
new file mode 100644
index 0000000000..d9dab1df9f
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/fuzz/mutators_byteslice.go
@@ -0,0 +1,313 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package fuzz
+
+// byteSliceRemoveBytes removes a random chunk of bytes from b.
+func byteSliceRemoveBytes(m *mutator, b []byte) []byte {
+	if len(b) <= 1 {
+		return nil
+	}
+	pos0 := m.rand(len(b))
+	pos1 := pos0 + m.chooseLen(len(b)-pos0)
+	copy(b[pos0:], b[pos1:])
+	b = b[:len(b)-(pos1-pos0)]
+	return b
+}
+
+// byteSliceInsertRandomBytes inserts a chunk of random bytes into b at a random
+// position.
+func byteSliceInsertRandomBytes(m *mutator, b []byte) []byte {
+	pos := m.rand(len(b) + 1)
+	n := m.chooseLen(1024)
+	if len(b)+n >= cap(b) {
+		return nil
+	}
+	b = b[:len(b)+n]
+	copy(b[pos+n:], b[pos:])
+	for i := 0; i < n; i++ {
+		b[pos+i] = byte(m.rand(256))
+	}
+	return b
+}
+
+// byteSliceDuplicateBytes duplicates a chunk of bytes in b and inserts it into
+// a random position.
+func byteSliceDuplicateBytes(m *mutator, b []byte) []byte {
+	if len(b) <= 1 {
+		return nil
+	}
+	src := m.rand(len(b))
+	dst := m.rand(len(b))
+	for dst == src {
+		dst = m.rand(len(b))
+	}
+	n := m.chooseLen(len(b) - src)
+	// Use the end of the slice as scratch space to avoid doing an
+	// allocation. If the slice is too small abort and try something
+	// else.
+	if len(b)+(n*2) >= cap(b) {
+		return nil
+	}
+	end := len(b)
+	// Increase the size of b to fit the duplicated block as well as
+	// some extra working space
+	b = b[:end+(n*2)]
+	// Copy the block of bytes we want to duplicate to the end of the
+	// slice
+	copy(b[end+n:], b[src:src+n])
+	// Shift the bytes after the splice point n positions to the right
+	// to make room for the new block
+	copy(b[dst+n:end+n], b[dst:end])
+	// Insert the duplicate block into the splice point
+	copy(b[dst:], b[end+n:])
+	b = b[:end+n]
+	return b
+}
+
+// byteSliceOverwriteBytes overwrites a chunk of b with another chunk of b.
+func byteSliceOverwriteBytes(m *mutator, b []byte) []byte {
+	if len(b) <= 1 {
+		return nil
+	}
+	src := m.rand(len(b))
+	dst := m.rand(len(b))
+	for dst == src {
+		dst = m.rand(len(b))
+	}
+	n := m.chooseLen(len(b) - src - 1)
+	copy(b[dst:], b[src:src+n])
+	return b
+}
+
+// byteSliceBitFlip flips a random bit in a random byte in b.
+func byteSliceBitFlip(m *mutator, b []byte) []byte {
+	if len(b) == 0 {
+		return nil
+	}
+	pos := m.rand(len(b))
+	b[pos] ^= 1 << uint(m.rand(8))
+	return b
+}
+
+// byteSliceXORByte XORs a random byte in b with a random value.
+func byteSliceXORByte(m *mutator, b []byte) []byte {
+	if len(b) == 0 {
+		return nil
+	}
+	pos := m.rand(len(b))
+	// In order to avoid a no-op (where the random value matches
+	// the existing value), use XOR instead of just setting to
+	// the random value.
+	b[pos] ^= byte(1 + m.rand(255))
+	return b
+}
+
+// byteSliceSwapByte swaps two random bytes in b.
+func byteSliceSwapByte(m *mutator, b []byte) []byte {
+	if len(b) <= 1 {
+		return nil
+	}
+	src := m.rand(len(b))
+	dst := m.rand(len(b))
+	for dst == src {
+		dst = m.rand(len(b))
+	}
+	b[src], b[dst] = b[dst], b[src]
+	return b
+}
+
+// byteSliceArithmeticUint8 adds/subtracts from a random byte in b.
+func byteSliceArithmeticUint8(m *mutator, b []byte) []byte {
+	if len(b) == 0 {
+		return nil
+	}
+	pos := m.rand(len(b))
+	v := byte(m.rand(35) + 1)
+	if m.r.bool() {
+		b[pos] += v
+	} else {
+		b[pos] -= v
+	}
+	return b
+}
+
+// byteSliceArithmeticUint16 adds/subtracts from a random uint16 in b.
+func byteSliceArithmeticUint16(m *mutator, b []byte) []byte {
+	if len(b) < 2 {
+		return nil
+	}
+	v := uint16(m.rand(35) + 1)
+	if m.r.bool() {
+		v = 0 - v
+	}
+	pos := m.rand(len(b) - 1)
+	enc := m.randByteOrder()
+	enc.PutUint16(b[pos:], enc.Uint16(b[pos:])+v)
+	return b
+}
+
+// byteSliceArithmeticUint32 adds/subtracts from a random uint32 in b.
+func byteSliceArithmeticUint32(m *mutator, b []byte) []byte {
+	if len(b) < 4 {
+		return nil
+	}
+	v := uint32(m.rand(35) + 1)
+	if m.r.bool() {
+		v = 0 - v
+	}
+	pos := m.rand(len(b) - 3)
+	enc := m.randByteOrder()
+	enc.PutUint32(b[pos:], enc.Uint32(b[pos:])+v)
+	return b
+}
+
+// byteSliceArithmeticUint64 adds/subtracts from a random uint64 in b.
+func byteSliceArithmeticUint64(m *mutator, b []byte) []byte {
+	if len(b) < 8 {
+		return nil
+	}
+	v := uint64(m.rand(35) + 1)
+	if m.r.bool() {
+		v = 0 - v
+	}
+	pos := m.rand(len(b) - 7)
+	enc := m.randByteOrder()
+	enc.PutUint64(b[pos:], enc.Uint64(b[pos:])+v)
+	return b
+}
+
+// byteSliceOverwriteInterestingUint8 overwrites a random byte in b with an interesting
+// value.
+func byteSliceOverwriteInterestingUint8(m *mutator, b []byte) []byte {
+	if len(b) == 0 {
+		return nil
+	}
+	pos := m.rand(len(b))
+	b[pos] = byte(interesting8[m.rand(len(interesting8))])
+	return b
+}
+
+// byteSliceOverwriteInterestingUint16 overwrites a random uint16 in b with an interesting
+// value.
+func byteSliceOverwriteInterestingUint16(m *mutator, b []byte) []byte {
+	if len(b) < 2 {
+		return nil
+	}
+	pos := m.rand(len(b) - 1)
+	v := uint16(interesting16[m.rand(len(interesting16))])
+	m.randByteOrder().PutUint16(b[pos:], v)
+	return b
+}
+
+// byteSliceOverwriteInterestingUint32 overwrites a random uint16 in b with an interesting
+// value.
+func byteSliceOverwriteInterestingUint32(m *mutator, b []byte) []byte {
+	if len(b) < 4 {
+		return nil
+	}
+	pos := m.rand(len(b) - 3)
+	v := uint32(interesting32[m.rand(len(interesting32))])
+	m.randByteOrder().PutUint32(b[pos:], v)
+	return b
+}
+
+// byteSliceInsertConstantBytes inserts a chunk of constant bytes into a random position in b.
+func byteSliceInsertConstantBytes(m *mutator, b []byte) []byte {
+	if len(b) <= 1 {
+		return nil
+	}
+	dst := m.rand(len(b))
+	// TODO(rolandshoemaker,katiehockman): 4096 was mainly picked
+	// randomly. We may want to either pick a much larger value
+	// (AFL uses 32768, paired with a similar impl to chooseLen
+	// which biases towards smaller lengths that grow over time),
+	// or set the max based on characteristics of the corpus
+	// (libFuzzer sets a min/max based on the min/max size of
+	// entries in the corpus and then picks uniformly from
+	// that range).
+	n := m.chooseLen(4096)
+	if len(b)+n >= cap(b) {
+		return nil
+	}
+	b = b[:len(b)+n]
+	copy(b[dst+n:], b[dst:])
+	rb := byte(m.rand(256))
+	for i := dst; i < dst+n; i++ {
+		b[i] = rb
+	}
+	return b
+}
+
+// byteSliceOverwriteConstantBytes overwrites a chunk of b with constant bytes.
+func byteSliceOverwriteConstantBytes(m *mutator, b []byte) []byte {
+	if len(b) <= 1 {
+		return nil
+	}
+	dst := m.rand(len(b))
+	n := m.chooseLen(len(b) - dst)
+	rb := byte(m.rand(256))
+	for i := dst; i < dst+n; i++ {
+		b[i] = rb
+	}
+	return b
+}
+
+// byteSliceShuffleBytes shuffles a chunk of bytes in b.
+func byteSliceShuffleBytes(m *mutator, b []byte) []byte {
+	if len(b) <= 1 {
+		return nil
+	}
+	dst := m.rand(len(b))
+	n := m.chooseLen(len(b) - dst)
+	if n <= 2 {
+		return nil
+	}
+	// Start at the end of the range, and iterate backwards
+	// to dst, swapping each element with another element in
+	// dst:dst+n (Fisher-Yates shuffle).
+	for i := n - 1; i > 0; i-- {
+		j := m.rand(i + 1)
+		b[dst+i], b[dst+j] = b[dst+j], b[dst+i]
+	}
+	return b
+}
+
+// byteSliceSwapBytes swaps two chunks of bytes in b.
+func byteSliceSwapBytes(m *mutator, b []byte) []byte {
+	if len(b) <= 1 {
+		return nil
+	}
+	src := m.rand(len(b))
+	dst := m.rand(len(b))
+	for dst == src {
+		dst = m.rand(len(b))
+	}
+	// Choose the random length as len(b) - max(src, dst)
+	// so that we don't attempt to swap a chunk that extends
+	// beyond the end of the slice
+	max := dst
+	if src > max {
+		max = src
+	}
+	n := m.chooseLen(len(b) - max - 1)
+	// Check that neither chunk intersect, so that we don't end up
+	// duplicating parts of the input, rather than swapping them
+	if src > dst && dst+n >= src || dst > src && src+n >= dst {
+		return nil
+	}
+	// Use the end of the slice as scratch space to avoid doing an
+	// allocation. If the slice is too small abort and try something
+	// else.
+	if len(b)+n >= cap(b) {
+		return nil
+	}
+	end := len(b)
+	b = b[:end+n]
+	copy(b[end:], b[dst:dst+n])
+	copy(b[dst:], b[src:src+n])
+	copy(b[src:], b[end:])
+	b = b[:end]
+	return b
+}
diff --git a/contrib/go/_std_1.20/src/internal/fuzz/pcg.go b/contrib/go/_std_1.20/src/internal/fuzz/pcg.go
new file mode 100644
index 0000000000..c9ea0afcf8
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/fuzz/pcg.go
@@ -0,0 +1,145 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package fuzz
+
+import (
+	"math/bits"
+	"os"
+	"strconv"
+	"strings"
+	"sync/atomic"
+	"time"
+)
+
+type mutatorRand interface {
+	uint32() uint32
+	intn(int) int
+	uint32n(uint32) uint32
+	exp2() int
+	bool() bool
+
+	save(randState, randInc *uint64)
+	restore(randState, randInc uint64)
+}
+
+// The functions in pcg implement a 32 bit PRNG with a 64 bit period: pcg xsh rr
+// 64 32. See https://www.pcg-random.org/ for more information. This
+// implementation is geared specifically towards the needs of fuzzing: Simple
+// creation and use, no reproducibility, no concurrency safety, just the
+// necessary methods, optimized for speed.
+
+var globalInc uint64 // PCG stream
+
+const multiplier uint64 = 6364136223846793005
+
+// pcgRand is a PRNG. It should not be copied or shared. No Rand methods are
+// concurrency safe.
+type pcgRand struct {
+	noCopy noCopy // help avoid mistakes: ask vet to ensure that we don't make a copy
+	state  uint64
+	inc    uint64
+}
+
+func godebugSeed() *int {
+	debug := strings.Split(os.Getenv("GODEBUG"), ",")
+	for _, f := range debug {
+		if strings.HasPrefix(f, "fuzzseed=") {
+			seed, err := strconv.Atoi(strings.TrimPrefix(f, "fuzzseed="))
+			if err != nil {
+				panic("malformed fuzzseed")
+			}
+			return &seed
+		}
+	}
+	return nil
+}
+
+// newPcgRand generates a new, seeded Rand, ready for use.
+func newPcgRand() *pcgRand {
+	r := new(pcgRand)
+	now := uint64(time.Now().UnixNano())
+	if seed := godebugSeed(); seed != nil {
+		now = uint64(*seed)
+	}
+	inc := atomic.AddUint64(&globalInc, 1)
+	r.state = now
+	r.inc = (inc << 1) | 1
+	r.step()
+	r.state += now
+	r.step()
+	return r
+}
+
+func (r *pcgRand) step() {
+	r.state *= multiplier
+	r.state += r.inc
+}
+
+func (r *pcgRand) save(randState, randInc *uint64) {
+	*randState = r.state
+	*randInc = r.inc
+}
+
+func (r *pcgRand) restore(randState, randInc uint64) {
+	r.state = randState
+	r.inc = randInc
+}
+
+// uint32 returns a pseudo-random uint32.
+func (r *pcgRand) uint32() uint32 {
+	x := r.state
+	r.step()
+	return bits.RotateLeft32(uint32(((x>>18)^x)>>27), -int(x>>59))
+}
+
+// intn returns a pseudo-random number in [0, n).
+// n must fit in a uint32.
+func (r *pcgRand) intn(n int) int {
+	if int(uint32(n)) != n {
+		panic("large Intn")
+	}
+	return int(r.uint32n(uint32(n)))
+}
+
+// uint32n returns a pseudo-random number in [0, n).
+//
+// For implementation details, see:
+// https://lemire.me/blog/2016/06/27/a-fast-alternative-to-the-modulo-reduction
+// https://lemire.me/blog/2016/06/30/fast-random-shuffling
+func (r *pcgRand) uint32n(n uint32) uint32 {
+	v := r.uint32()
+	prod := uint64(v) * uint64(n)
+	low := uint32(prod)
+	if low < n {
+		thresh := uint32(-int32(n)) % n
+		for low < thresh {
+			v = r.uint32()
+			prod = uint64(v) * uint64(n)
+			low = uint32(prod)
+		}
+	}
+	return uint32(prod >> 32)
+}
+
+// exp2 generates n with probability 1/2^(n+1).
+func (r *pcgRand) exp2() int {
+	return bits.TrailingZeros32(r.uint32())
+}
+
+// bool generates a random bool.
+func (r *pcgRand) bool() bool {
+	return r.uint32()&1 == 0
+}
+
+// noCopy may be embedded into structs which must not be copied
+// after the first use.
+//
+// See https://golang.org/issues/8005#issuecomment-190753527
+// for details.
+type noCopy struct{}
+
+// lock is a no-op used by -copylocks checker from `go vet`.
+func (*noCopy) lock()   {}
+func (*noCopy) unlock() {}
diff --git a/contrib/go/_std_1.20/src/internal/fuzz/queue.go b/contrib/go/_std_1.20/src/internal/fuzz/queue.go
new file mode 100644
index 0000000000..195d6eb7b6
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/fuzz/queue.go
@@ -0,0 +1,71 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package fuzz
+
+// queue holds a growable sequence of inputs for fuzzing and minimization.
+//
+// For now, this is a simple ring buffer
+// (https://en.wikipedia.org/wiki/Circular_buffer).
+//
+// TODO(golang.org/issue/46224): use a prioritization algorithm based on input
+// size, previous duration, coverage, and any other metrics that seem useful.
+type queue struct {
+	// elems holds a ring buffer.
+	// The queue is empty when begin = end.
+	// The queue is full (until grow is called) when end = begin + N - 1 (mod N)
+	// where N = cap(elems).
+	elems     []any
+	head, len int
+}
+
+func (q *queue) cap() int {
+	return len(q.elems)
+}
+
+func (q *queue) grow() {
+	oldCap := q.cap()
+	newCap := oldCap * 2
+	if newCap == 0 {
+		newCap = 8
+	}
+	newElems := make([]any, newCap)
+	oldLen := q.len
+	for i := 0; i < oldLen; i++ {
+		newElems[i] = q.elems[(q.head+i)%oldCap]
+	}
+	q.elems = newElems
+	q.head = 0
+}
+
+func (q *queue) enqueue(e any) {
+	if q.len+1 > q.cap() {
+		q.grow()
+	}
+	i := (q.head + q.len) % q.cap()
+	q.elems[i] = e
+	q.len++
+}
+
+func (q *queue) dequeue() (any, bool) {
+	if q.len == 0 {
+		return nil, false
+	}
+	e := q.elems[q.head]
+	q.elems[q.head] = nil
+	q.head = (q.head + 1) % q.cap()
+	q.len--
+	return e, true
+}
+
+func (q *queue) peek() (any, bool) {
+	if q.len == 0 {
+		return nil, false
+	}
+	return q.elems[q.head], true
+}
+
+func (q *queue) clear() {
+	*q = queue{}
+}
diff --git a/contrib/go/_std_1.20/src/internal/fuzz/sys_posix.go b/contrib/go/_std_1.20/src/internal/fuzz/sys_posix.go
new file mode 100644
index 0000000000..fec6054f67
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/fuzz/sys_posix.go
@@ -0,0 +1,130 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build darwin || freebsd || linux
+
+package fuzz
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"syscall"
+)
+
+type sharedMemSys struct{}
+
+func sharedMemMapFile(f *os.File, size int, removeOnClose bool) (*sharedMem, error) {
+	prot := syscall.PROT_READ | syscall.PROT_WRITE
+	flags := syscall.MAP_FILE | syscall.MAP_SHARED
+	region, err := syscall.Mmap(int(f.Fd()), 0, size, prot, flags)
+	if err != nil {
+		return nil, err
+	}
+
+	return &sharedMem{f: f, region: region, removeOnClose: removeOnClose}, nil
+}
+
+// Close unmaps the shared memory and closes the temporary file. If this
+// sharedMem was created with sharedMemTempFile, Close also removes the file.
+func (m *sharedMem) Close() error {
+	// Attempt all operations, even if we get an error for an earlier operation.
+	// os.File.Close may fail due to I/O errors, but we still want to delete
+	// the temporary file.
+	var errs []error
+	errs = append(errs,
+		syscall.Munmap(m.region),
+		m.f.Close())
+	if m.removeOnClose {
+		errs = append(errs, os.Remove(m.f.Name()))
+	}
+	for _, err := range errs {
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// setWorkerComm configures communication channels on the cmd that will
+// run a worker process.
+func setWorkerComm(cmd *exec.Cmd, comm workerComm) {
+	mem := <-comm.memMu
+	memFile := mem.f
+	comm.memMu <- mem
+	cmd.ExtraFiles = []*os.File{comm.fuzzIn, comm.fuzzOut, memFile}
+}
+
+// getWorkerComm returns communication channels in the worker process.
+func getWorkerComm() (comm workerComm, err error) {
+	fuzzIn := os.NewFile(3, "fuzz_in")
+	fuzzOut := os.NewFile(4, "fuzz_out")
+	memFile := os.NewFile(5, "fuzz_mem")
+	fi, err := memFile.Stat()
+	if err != nil {
+		return workerComm{}, err
+	}
+	size := int(fi.Size())
+	if int64(size) != fi.Size() {
+		return workerComm{}, fmt.Errorf("fuzz temp file exceeds maximum size")
+	}
+	removeOnClose := false
+	mem, err := sharedMemMapFile(memFile, size, removeOnClose)
+	if err != nil {
+		return workerComm{}, err
+	}
+	memMu := make(chan *sharedMem, 1)
+	memMu <- mem
+	return workerComm{fuzzIn: fuzzIn, fuzzOut: fuzzOut, memMu: memMu}, nil
+}
+
+// isInterruptError returns whether an error was returned by a process that
+// was terminated by an interrupt signal (SIGINT).
+func isInterruptError(err error) bool {
+	exitErr, ok := err.(*exec.ExitError)
+	if !ok || exitErr.ExitCode() >= 0 {
+		return false
+	}
+	status := exitErr.Sys().(syscall.WaitStatus)
+	return status.Signal() == syscall.SIGINT
+}
+
+// terminationSignal checks if err is an exec.ExitError with a signal status.
+// If it is, terminationSignal returns the signal and true.
+// If not, -1 and false.
+func terminationSignal(err error) (os.Signal, bool) {
+	exitErr, ok := err.(*exec.ExitError)
+	if !ok || exitErr.ExitCode() >= 0 {
+		return syscall.Signal(-1), false
+	}
+	status := exitErr.Sys().(syscall.WaitStatus)
+	return status.Signal(), status.Signaled()
+}
+
+// isCrashSignal returns whether a signal was likely to have been caused by an
+// error in the program that received it, triggered by a fuzz input. For
+// example, SIGSEGV would be received after a nil pointer dereference.
+// Other signals like SIGKILL or SIGHUP are more likely to have been sent by
+// another process, and we shouldn't record a crasher if the worker process
+// receives one of these.
+//
+// Note that Go installs its own signal handlers on startup, so some of these
+// signals may only be received if signal handlers are changed. For example,
+// SIGSEGV is normally transformed into a panic that causes the process to exit
+// with status 2 if not recovered, which we handle as a crash.
+func isCrashSignal(signal os.Signal) bool {
+	switch signal {
+	case
+		syscall.SIGILL,  // illegal instruction
+		syscall.SIGTRAP, // breakpoint
+		syscall.SIGABRT, // abort() called
+		syscall.SIGBUS,  // invalid memory access (e.g., misaligned address)
+		syscall.SIGFPE,  // math error, e.g., integer divide by zero
+		syscall.SIGSEGV, // invalid memory access (e.g., write to read-only)
+		syscall.SIGPIPE: // sent data to closed pipe or socket
+		return true
+	default:
+		return false
+	}
+}
diff --git a/contrib/go/_std_1.20/src/internal/fuzz/sys_windows.go b/contrib/go/_std_1.20/src/internal/fuzz/sys_windows.go
new file mode 100644
index 0000000000..aa85be7e1c
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/fuzz/sys_windows.go
@@ -0,0 +1,147 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package fuzz
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"syscall"
+	"unsafe"
+)
+
+type sharedMemSys struct {
+	mapObj syscall.Handle
+}
+
+func sharedMemMapFile(f *os.File, size int, removeOnClose bool) (mem *sharedMem, err error) {
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("mapping temporary file %s: %w", f.Name(), err)
+		}
+	}()
+
+	// Create a file mapping object. The object itself is not shared.
+	mapObj, err := syscall.CreateFileMapping(
+		syscall.Handle(f.Fd()), // fhandle
+		nil,                    // sa
+		syscall.PAGE_READWRITE, // prot
+		0,                      // maxSizeHigh
+		0,                      // maxSizeLow
+		nil,                    // name
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	// Create a view from the file mapping object.
+	access := uint32(syscall.FILE_MAP_READ | syscall.FILE_MAP_WRITE)
+	addr, err := syscall.MapViewOfFile(
+		mapObj,        // handle
+		access,        // access
+		0,             // offsetHigh
+		0,             // offsetLow
+		uintptr(size), // length
+	)
+	if err != nil {
+		syscall.CloseHandle(mapObj)
+		return nil, err
+	}
+
+	region := unsafe.Slice((*byte)(unsafe.Pointer(addr)), size)
+	return &sharedMem{
+		f:             f,
+		region:        region,
+		removeOnClose: removeOnClose,
+		sys:           sharedMemSys{mapObj: mapObj},
+	}, nil
+}
+
+// Close unmaps the shared memory and closes the temporary file. If this
+// sharedMem was created with sharedMemTempFile, Close also removes the file.
+func (m *sharedMem) Close() error {
+	// Attempt all operations, even if we get an error for an earlier operation.
+	// os.File.Close may fail due to I/O errors, but we still want to delete
+	// the temporary file.
+	var errs []error
+	errs = append(errs,
+		syscall.UnmapViewOfFile(uintptr(unsafe.Pointer(&m.region[0]))),
+		syscall.CloseHandle(m.sys.mapObj),
+		m.f.Close())
+	if m.removeOnClose {
+		errs = append(errs, os.Remove(m.f.Name()))
+	}
+	for _, err := range errs {
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// setWorkerComm configures communication channels on the cmd that will
+// run a worker process.
+func setWorkerComm(cmd *exec.Cmd, comm workerComm) {
+	mem := <-comm.memMu
+	memName := mem.f.Name()
+	comm.memMu <- mem
+	syscall.SetHandleInformation(syscall.Handle(comm.fuzzIn.Fd()), syscall.HANDLE_FLAG_INHERIT, 1)
+	syscall.SetHandleInformation(syscall.Handle(comm.fuzzOut.Fd()), syscall.HANDLE_FLAG_INHERIT, 1)
+	cmd.Env = append(cmd.Env, fmt.Sprintf("GO_TEST_FUZZ_WORKER_HANDLES=%x,%x,%q", comm.fuzzIn.Fd(), comm.fuzzOut.Fd(), memName))
+	cmd.SysProcAttr = &syscall.SysProcAttr{AdditionalInheritedHandles: []syscall.Handle{syscall.Handle(comm.fuzzIn.Fd()), syscall.Handle(comm.fuzzOut.Fd())}}
+}
+
+// getWorkerComm returns communication channels in the worker process.
+func getWorkerComm() (comm workerComm, err error) {
+	v := os.Getenv("GO_TEST_FUZZ_WORKER_HANDLES")
+	if v == "" {
+		return workerComm{}, fmt.Errorf("GO_TEST_FUZZ_WORKER_HANDLES not set")
+	}
+	var fuzzInFD, fuzzOutFD uintptr
+	var memName string
+	if _, err := fmt.Sscanf(v, "%x,%x,%q", &fuzzInFD, &fuzzOutFD, &memName); err != nil {
+		return workerComm{}, fmt.Errorf("parsing GO_TEST_FUZZ_WORKER_HANDLES=%s: %v", v, err)
+	}
+
+	fuzzIn := os.NewFile(fuzzInFD, "fuzz_in")
+	fuzzOut := os.NewFile(fuzzOutFD, "fuzz_out")
+	tmpFile, err := os.OpenFile(memName, os.O_RDWR, 0)
+	if err != nil {
+		return workerComm{}, fmt.Errorf("worker opening temp file: %w", err)
+	}
+	fi, err := tmpFile.Stat()
+	if err != nil {
+		return workerComm{}, fmt.Errorf("worker checking temp file size: %w", err)
+	}
+	size := int(fi.Size())
+	if int64(size) != fi.Size() {
+		return workerComm{}, fmt.Errorf("fuzz temp file exceeds maximum size")
+	}
+	removeOnClose := false
+	mem, err := sharedMemMapFile(tmpFile, size, removeOnClose)
+	if err != nil {
+		return workerComm{}, err
+	}
+	memMu := make(chan *sharedMem, 1)
+	memMu <- mem
+
+	return workerComm{fuzzIn: fuzzIn, fuzzOut: fuzzOut, memMu: memMu}, nil
+}
+
+func isInterruptError(err error) bool {
+	// On Windows, we can't tell whether the process was interrupted by the error
+	// returned by Wait. It looks like an ExitError with status 1.
+	return false
+}
+
+// terminationSignal returns -1 and false because Windows doesn't have signals.
+func terminationSignal(err error) (os.Signal, bool) {
+	return syscall.Signal(-1), false
+}
+
+// isCrashSignal is not implemented because Windows doesn't have signals.
+func isCrashSignal(signal os.Signal) bool {
+	panic("not implemented: no signals on windows")
+}
diff --git a/contrib/go/_std_1.20/src/internal/fuzz/trace.go b/contrib/go/_std_1.20/src/internal/fuzz/trace.go
new file mode 100644
index 0000000000..b471914850
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/fuzz/trace.go
@@ -0,0 +1,36 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !libfuzzer
+
+package fuzz
+
+import _ "unsafe"
+// for go:linkname
+
+//go:linkname libfuzzerTraceCmp1 runtime.libfuzzerTraceCmp1
+//go:linkname libfuzzerTraceCmp2 runtime.libfuzzerTraceCmp2
+//go:linkname libfuzzerTraceCmp4 runtime.libfuzzerTraceCmp4
+//go:linkname libfuzzerTraceCmp8 runtime.libfuzzerTraceCmp8
+
+//go:linkname libfuzzerTraceConstCmp1 runtime.libfuzzerTraceConstCmp1
+//go:linkname libfuzzerTraceConstCmp2 runtime.libfuzzerTraceConstCmp2
+//go:linkname libfuzzerTraceConstCmp4 runtime.libfuzzerTraceConstCmp4
+//go:linkname libfuzzerTraceConstCmp8 runtime.libfuzzerTraceConstCmp8
+
+//go:linkname libfuzzerHookStrCmp runtime.libfuzzerHookStrCmp
+//go:linkname libfuzzerHookEqualFold runtime.libfuzzerHookEqualFold
+
+func libfuzzerTraceCmp1(arg0, arg1 uint8, fakePC uint)  {}
+func libfuzzerTraceCmp2(arg0, arg1 uint16, fakePC uint) {}
+func libfuzzerTraceCmp4(arg0, arg1 uint32, fakePC uint) {}
+func libfuzzerTraceCmp8(arg0, arg1 uint64, fakePC uint) {}
+
+func libfuzzerTraceConstCmp1(arg0, arg1 uint8, fakePC uint)  {}
+func libfuzzerTraceConstCmp2(arg0, arg1 uint16, fakePC uint) {}
+func libfuzzerTraceConstCmp4(arg0, arg1 uint32, fakePC uint) {}
+func libfuzzerTraceConstCmp8(arg0, arg1 uint64, fakePC uint) {}
+
+func libfuzzerHookStrCmp(arg0, arg1 string, fakePC uint)    {}
+func libfuzzerHookEqualFold(arg0, arg1 string, fakePC uint) {}
diff --git a/contrib/go/_std_1.20/src/internal/fuzz/worker.go b/contrib/go/_std_1.20/src/internal/fuzz/worker.go
new file mode 100644
index 0000000000..467c39bdc9
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/fuzz/worker.go
@@ -0,0 +1,1184 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package fuzz
+
+import (
+	"bytes"
+	"context"
+	"crypto/sha256"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
+	"reflect"
+	"runtime"
+	"sync"
+	"time"
+)
+
+const (
+	// workerFuzzDuration is the amount of time a worker can spend testing random
+	// variations of an input given by the coordinator.
+	workerFuzzDuration = 100 * time.Millisecond
+
+	// workerTimeoutDuration is the amount of time a worker can go without
+	// responding to the coordinator before being stopped.
+	workerTimeoutDuration = 1 * time.Second
+
+	// workerExitCode is used as an exit code by fuzz worker processes after an internal error.
+	// This distinguishes internal errors from uncontrolled panics and other crashes.
+	// Keep in sync with internal/fuzz.workerExitCode.
+	workerExitCode = 70
+
+	// workerSharedMemSize is the maximum size of the shared memory file used to
+	// communicate with workers. This limits the size of fuzz inputs.
+	workerSharedMemSize = 100 << 20 // 100 MB
+)
+
+// worker manages a worker process running a test binary. The worker object
+// exists only in the coordinator (the process started by 'go test -fuzz').
+// workerClient is used by the coordinator to send RPCs to the worker process,
+// which handles them with workerServer.
+type worker struct {
+	dir     string   // working directory, same as package directory
+	binPath string   // path to test executable
+	args    []string // arguments for test executable
+	env     []string // environment for test executable
+
+	coordinator *coordinator
+
+	memMu chan *sharedMem // mutex guarding shared memory with worker; persists across processes.
+
+	cmd         *exec.Cmd     // current worker process
+	client      *workerClient // used to communicate with worker process
+	waitErr     error         // last error returned by wait, set before termC is closed.
+	interrupted bool          // true after stop interrupts a running worker.
+	termC       chan struct{} // closed by wait when worker process terminates
+}
+
+func newWorker(c *coordinator, dir, binPath string, args, env []string) (*worker, error) {
+	mem, err := sharedMemTempFile(workerSharedMemSize)
+	if err != nil {
+		return nil, err
+	}
+	memMu := make(chan *sharedMem, 1)
+	memMu <- mem
+	return &worker{
+		dir:         dir,
+		binPath:     binPath,
+		args:        args,
+		env:         env[:len(env):len(env)], // copy on append to ensure workers don't overwrite each other.
+		coordinator: c,
+		memMu:       memMu,
+	}, nil
+}
+
+// cleanup releases persistent resources associated with the worker.
+func (w *worker) cleanup() error {
+	mem := <-w.memMu
+	if mem == nil {
+		return nil
+	}
+	close(w.memMu)
+	return mem.Close()
+}
+
+// coordinate runs the test binary to perform fuzzing.
+//
+// coordinate loops until ctx is cancelled or a fatal error is encountered.
+// If a test process terminates unexpectedly while fuzzing, coordinate will
+// attempt to restart and continue unless the termination can be attributed
+// to an interruption (from a timer or the user).
+//
+// While looping, coordinate receives inputs from the coordinator, passes
+// those inputs to the worker process, then passes the results back to
+// the coordinator.
+func (w *worker) coordinate(ctx context.Context) error {
+	// Main event loop.
+	for {
+		// Start or restart the worker if it's not running.
+		if !w.isRunning() {
+			if err := w.startAndPing(ctx); err != nil {
+				return err
+			}
+		}
+
+		select {
+		case <-ctx.Done():
+			// Worker was told to stop.
+			err := w.stop()
+			if err != nil && !w.interrupted && !isInterruptError(err) {
+				return err
+			}
+			return ctx.Err()
+
+		case <-w.termC:
+			// Worker process terminated unexpectedly while waiting for input.
+			err := w.stop()
+			if w.interrupted {
+				panic("worker interrupted after unexpected termination")
+			}
+			if err == nil || isInterruptError(err) {
+				// Worker stopped, either by exiting with status 0 or after being
+				// interrupted with a signal that was not sent by the coordinator.
+				//
+				// When the user presses ^C, on POSIX platforms, SIGINT is delivered to
+				// all processes in the group concurrently, and the worker may see it
+				// before the coordinator. The worker should exit 0 gracefully (in
+				// theory).
+				//
+				// This condition is probably intended by the user, so suppress
+				// the error.
+				return nil
+			}
+			if exitErr, ok := err.(*exec.ExitError); ok && exitErr.ExitCode() == workerExitCode {
+				// Worker exited with a code indicating F.Fuzz was not called correctly,
+				// for example, F.Fail was called first.
+				return fmt.Errorf("fuzzing process exited unexpectedly due to an internal failure: %w", err)
+			}
+			// Worker exited non-zero or was terminated by a non-interrupt
+			// signal (for example, SIGSEGV) while fuzzing.
+			return fmt.Errorf("fuzzing process hung or terminated unexpectedly: %w", err)
+			// TODO(jayconrod,katiehockman): if -keepfuzzing, restart worker.
+
+		case input := <-w.coordinator.inputC:
+			// Received input from coordinator.
+			args := fuzzArgs{
+				Limit:        input.limit,
+				Timeout:      input.timeout,
+				Warmup:       input.warmup,
+				CoverageData: input.coverageData,
+			}
+			entry, resp, isInternalError, err := w.client.fuzz(ctx, input.entry, args)
+			canMinimize := true
+			if err != nil {
+				// Error communicating with worker.
+				w.stop()
+				if ctx.Err() != nil {
+					// Timeout or interruption.
+					return ctx.Err()
+				}
+				if w.interrupted {
+					// Communication error before we stopped the worker.
+					// Report an error, but don't record a crasher.
+					return fmt.Errorf("communicating with fuzzing process: %v", err)
+				}
+				if sig, ok := terminationSignal(w.waitErr); ok && !isCrashSignal(sig) {
+					// Worker terminated by a signal that probably wasn't caused by a
+					// specific input to the fuzz function. For example, on Linux,
+					// the kernel (OOM killer) may send SIGKILL to a process using a lot
+					// of memory. Or the shell might send SIGHUP when the terminal
+					// is closed. Don't record a crasher.
+					return fmt.Errorf("fuzzing process terminated by unexpected signal; no crash will be recorded: %v", w.waitErr)
+				}
+				if isInternalError {
+					// An internal error occurred which shouldn't be considered
+					// a crash.
+					return err
+				}
+				// Unexpected termination. Set error message and fall through.
+				// We'll restart the worker on the next iteration.
+				// Don't attempt to minimize this since it crashed the worker.
+				resp.Err = fmt.Sprintf("fuzzing process hung or terminated unexpectedly: %v", w.waitErr)
+				canMinimize = false
+			}
+			result := fuzzResult{
+				limit:         input.limit,
+				count:         resp.Count,
+				totalDuration: resp.TotalDuration,
+				entryDuration: resp.InterestingDuration,
+				entry:         entry,
+				crasherMsg:    resp.Err,
+				coverageData:  resp.CoverageData,
+				canMinimize:   canMinimize,
+			}
+			w.coordinator.resultC <- result
+
+		case input := <-w.coordinator.minimizeC:
+			// Received input to minimize from coordinator.
+			result, err := w.minimize(ctx, input)
+			if err != nil {
+				// Error minimizing. Send back the original input. If it didn't cause
+				// an error before, report it as causing an error now.
+				// TODO: double-check this is handled correctly when
+				// implementing -keepfuzzing.
+				result = fuzzResult{
+					entry:       input.entry,
+					crasherMsg:  input.crasherMsg,
+					canMinimize: false,
+					limit:       input.limit,
+				}
+				if result.crasherMsg == "" {
+					result.crasherMsg = err.Error()
+				}
+			}
+			w.coordinator.resultC <- result
+		}
+	}
+}
+
+// minimize tells a worker process to attempt to find a smaller value that
+// either causes an error (if we started minimizing because we found an input
+// that causes an error) or preserves new coverage (if we started minimizing
+// because we found an input that expands coverage).
+func (w *worker) minimize(ctx context.Context, input fuzzMinimizeInput) (min fuzzResult, err error) {
+	if w.coordinator.opts.MinimizeTimeout != 0 {
+		var cancel func()
+		ctx, cancel = context.WithTimeout(ctx, w.coordinator.opts.MinimizeTimeout)
+		defer cancel()
+	}
+
+	args := minimizeArgs{
+		Limit:        input.limit,
+		Timeout:      input.timeout,
+		KeepCoverage: input.keepCoverage,
+	}
+	entry, resp, err := w.client.minimize(ctx, input.entry, args)
+	if err != nil {
+		// Error communicating with worker.
+		w.stop()
+		if ctx.Err() != nil || w.interrupted || isInterruptError(w.waitErr) {
+			// Worker was interrupted, possibly by the user pressing ^C.
+			// Normally, workers can handle interrupts and timeouts gracefully and
+			// will return without error. An error here indicates the worker
+			// may not have been in a good state, but the error won't be meaningful
+			// to the user. Just return the original crasher without logging anything.
+			return fuzzResult{
+				entry:        input.entry,
+				crasherMsg:   input.crasherMsg,
+				coverageData: input.keepCoverage,
+				canMinimize:  false,
+				limit:        input.limit,
+			}, nil
+		}
+		return fuzzResult{
+			entry:         entry,
+			crasherMsg:    fmt.Sprintf("fuzzing process hung or terminated unexpectedly while minimizing: %v", err),
+			canMinimize:   false,
+			limit:         input.limit,
+			count:         resp.Count,
+			totalDuration: resp.Duration,
+		}, nil
+	}
+
+	if input.crasherMsg != "" && resp.Err == "" {
+		return fuzzResult{}, fmt.Errorf("attempted to minimize a crash but could not reproduce")
+	}
+
+	return fuzzResult{
+		entry:         entry,
+		crasherMsg:    resp.Err,
+		coverageData:  resp.CoverageData,
+		canMinimize:   false,
+		limit:         input.limit,
+		count:         resp.Count,
+		totalDuration: resp.Duration,
+	}, nil
+}
+
+func (w *worker) isRunning() bool {
+	return w.cmd != nil
+}
+
+// startAndPing starts the worker process and sends it a message to make sure it
+// can communicate.
+//
+// startAndPing returns an error if any part of this didn't work, including if
+// the context is expired or the worker process was interrupted before it
+// responded. Errors that happen after start but before the ping response
+// likely indicate that the worker did not call F.Fuzz or called F.Fail first.
+// We don't record crashers for these errors.
+func (w *worker) startAndPing(ctx context.Context) error {
+	if ctx.Err() != nil {
+		return ctx.Err()
+	}
+	if err := w.start(); err != nil {
+		return err
+	}
+	if err := w.client.ping(ctx); err != nil {
+		w.stop()
+		if ctx.Err() != nil {
+			return ctx.Err()
+		}
+		if isInterruptError(err) {
+			// User may have pressed ^C before worker responded.
+			return err
+		}
+		// TODO: record and return stderr.
+		return fmt.Errorf("fuzzing process terminated without fuzzing: %w", err)
+	}
+	return nil
+}
+
+// start runs a new worker process.
+//
+// If the process couldn't be started, start returns an error. Start won't
+// return later termination errors from the process if they occur.
+//
+// If the process starts successfully, start returns nil. stop must be called
+// once later to clean up, even if the process terminates on its own.
+//
+// When the process terminates, w.waitErr is set to the error (if any), and
+// w.termC is closed.
+func (w *worker) start() (err error) {
+	if w.isRunning() {
+		panic("worker already started")
+	}
+	w.waitErr = nil
+	w.interrupted = false
+	w.termC = nil
+
+	cmd := exec.Command(w.binPath, w.args...)
+	cmd.Dir = w.dir
+	cmd.Env = w.env[:len(w.env):len(w.env)] // copy on append to ensure workers don't overwrite each other.
+
+	// Create the "fuzz_in" and "fuzz_out" pipes so we can communicate with
+	// the worker. We don't use stdin and stdout, since the test binary may
+	// do something else with those.
+	//
+	// Each pipe has a reader and a writer. The coordinator writes to fuzzInW
+	// and reads from fuzzOutR. The worker inherits fuzzInR and fuzzOutW.
+	// The coordinator closes fuzzInR and fuzzOutW after starting the worker,
+	// since we have no further need of them.
+	fuzzInR, fuzzInW, err := os.Pipe()
+	if err != nil {
+		return err
+	}
+	defer fuzzInR.Close()
+	fuzzOutR, fuzzOutW, err := os.Pipe()
+	if err != nil {
+		fuzzInW.Close()
+		return err
+	}
+	defer fuzzOutW.Close()
+	setWorkerComm(cmd, workerComm{fuzzIn: fuzzInR, fuzzOut: fuzzOutW, memMu: w.memMu})
+
+	// Start the worker process.
+	if err := cmd.Start(); err != nil {
+		fuzzInW.Close()
+		fuzzOutR.Close()
+		return err
+	}
+
+	// Worker started successfully.
+	// After this, w.client owns fuzzInW and fuzzOutR, so w.client.Close must be
+	// called later by stop.
+	w.cmd = cmd
+	w.termC = make(chan struct{})
+	comm := workerComm{fuzzIn: fuzzInW, fuzzOut: fuzzOutR, memMu: w.memMu}
+	m := newMutator()
+	w.client = newWorkerClient(comm, m)
+
+	go func() {
+		w.waitErr = w.cmd.Wait()
+		close(w.termC)
+	}()
+
+	return nil
+}
+
+// stop tells the worker process to exit by closing w.client, then blocks until
+// it terminates. If the worker doesn't terminate after a short time, stop
+// signals it with os.Interrupt (where supported), then os.Kill.
+//
+// stop returns the error the process terminated with, if any (same as
+// w.waitErr).
+//
+// stop must be called at least once after start returns successfully, even if
+// the worker process terminates unexpectedly.
+func (w *worker) stop() error {
+	if w.termC == nil {
+		panic("worker was not started successfully")
+	}
+	select {
+	case <-w.termC:
+		// Worker already terminated.
+		if w.client == nil {
+			// stop already called.
+			return w.waitErr
+		}
+		// Possible unexpected termination.
+		w.client.Close()
+		w.cmd = nil
+		w.client = nil
+		return w.waitErr
+	default:
+		// Worker still running.
+	}
+
+	// Tell the worker to stop by closing fuzz_in. It won't actually stop until it
+	// finishes with earlier calls.
+	closeC := make(chan struct{})
+	go func() {
+		w.client.Close()
+		close(closeC)
+	}()
+
+	sig := os.Interrupt
+	if runtime.GOOS == "windows" {
+		// Per https://golang.org/pkg/os/#Signal, “Interrupt is not implemented on
+		// Windows; using it with os.Process.Signal will return an error.”
+		// Fall back to Kill instead.
+		sig = os.Kill
+	}
+
+	t := time.NewTimer(workerTimeoutDuration)
+	for {
+		select {
+		case <-w.termC:
+			// Worker terminated.
+			t.Stop()
+			<-closeC
+			w.cmd = nil
+			w.client = nil
+			return w.waitErr
+
+		case <-t.C:
+			// Timer fired before worker terminated.
+			w.interrupted = true
+			switch sig {
+			case os.Interrupt:
+				// Try to stop the worker with SIGINT and wait a little longer.
+				w.cmd.Process.Signal(sig)
+				sig = os.Kill
+				t.Reset(workerTimeoutDuration)
+
+			case os.Kill:
+				// Try to stop the worker with SIGKILL and keep waiting.
+				w.cmd.Process.Signal(sig)
+				sig = nil
+				t.Reset(workerTimeoutDuration)
+
+			case nil:
+				// Still waiting. Print a message to let the user know why.
+				fmt.Fprintf(w.coordinator.opts.Log, "waiting for fuzzing process to terminate...\n")
+			}
+		}
+	}
+}
+
+// RunFuzzWorker is called in a worker process to communicate with the
+// coordinator process in order to fuzz random inputs. RunFuzzWorker loops
+// until the coordinator tells it to stop.
+//
+// fn is a wrapper on the fuzz function. It may return an error to indicate
+// a given input "crashed". The coordinator will also record a crasher if
+// the function times out or terminates the process.
+//
+// RunFuzzWorker returns an error if it could not communicate with the
+// coordinator process.
+func RunFuzzWorker(ctx context.Context, fn func(CorpusEntry) error) error {
+	comm, err := getWorkerComm()
+	if err != nil {
+		return err
+	}
+	srv := &workerServer{
+		workerComm: comm,
+		fuzzFn: func(e CorpusEntry) (time.Duration, error) {
+			timer := time.AfterFunc(10*time.Second, func() {
+				panic("deadlocked!") // this error message won't be printed
+			})
+			defer timer.Stop()
+			start := time.Now()
+			err := fn(e)
+			return time.Since(start), err
+		},
+		m: newMutator(),
+	}
+	return srv.serve(ctx)
+}
+
+// call is serialized and sent from the coordinator on fuzz_in. It acts as
+// a minimalist RPC mechanism. Exactly one of its fields must be set to indicate
+// which method to call.
+type call struct {
+	Ping     *pingArgs
+	Fuzz     *fuzzArgs
+	Minimize *minimizeArgs
+}
+
+// minimizeArgs contains arguments to workerServer.minimize. The value to
+// minimize is already in shared memory.
+type minimizeArgs struct {
+	// Timeout is the time to spend minimizing. This may include time to start up,
+	// especially if the input causes the worker process to terminated, requiring
+	// repeated restarts.
+	Timeout time.Duration
+
+	// Limit is the maximum number of values to test, without spending more time
+	// than Duration. 0 indicates no limit.
+	Limit int64
+
+	// KeepCoverage is a set of coverage counters the worker should attempt to
+	// keep in minimized values. When provided, the worker will reject inputs that
+	// don't cause at least one of these bits to be set.
+	KeepCoverage []byte
+
+	// Index is the index of the fuzz target parameter to be minimized.
+	Index int
+}
+
+// minimizeResponse contains results from workerServer.minimize.
+type minimizeResponse struct {
+	// WroteToMem is true if the worker found a smaller input and wrote it to
+	// shared memory. If minimizeArgs.KeepCoverage was set, the minimized input
+	// preserved at least one coverage bit and did not cause an error.
+	// Otherwise, the minimized input caused some error, recorded in Err.
+	WroteToMem bool
+
+	// Err is the error string caused by the value in shared memory, if any.
+	Err string
+
+	// CoverageData is the set of coverage bits activated by the minimized value
+	// in shared memory. When set, it contains at least one bit from KeepCoverage.
+	// CoverageData will be nil if Err is set or if minimization failed.
+	CoverageData []byte
+
+	// Duration is the time spent minimizing, not including starting or cleaning up.
+	Duration time.Duration
+
+	// Count is the number of values tested.
+	Count int64
+}
+
+// fuzzArgs contains arguments to workerServer.fuzz. The value to fuzz is
+// passed in shared memory.
+type fuzzArgs struct {
+	// Timeout is the time to spend fuzzing, not including starting or
+	// cleaning up.
+	Timeout time.Duration
+
+	// Limit is the maximum number of values to test, without spending more time
+	// than Duration. 0 indicates no limit.
+	Limit int64
+
+	// Warmup indicates whether this is part of a warmup run, meaning that
+	// fuzzing should not occur. If coverageEnabled is true, then coverage data
+	// should be reported.
+	Warmup bool
+
+	// CoverageData is the coverage data. If set, the worker should update its
+	// local coverage data prior to fuzzing.
+	CoverageData []byte
+}
+
+// fuzzResponse contains results from workerServer.fuzz.
+type fuzzResponse struct {
+	// Duration is the time spent fuzzing, not including starting or cleaning up.
+	TotalDuration       time.Duration
+	InterestingDuration time.Duration
+
+	// Count is the number of values tested.
+	Count int64
+
+	// CoverageData is set if the value in shared memory expands coverage
+	// and therefore may be interesting to the coordinator.
+	CoverageData []byte
+
+	// Err is the error string caused by the value in shared memory, which is
+	// non-empty if the value in shared memory caused a crash.
+	Err string
+
+	// InternalErr is the error string caused by an internal error in the
+	// worker. This shouldn't be considered a crasher.
+	InternalErr string
+}
+
+// pingArgs contains arguments to workerServer.ping.
+type pingArgs struct{}
+
+// pingResponse contains results from workerServer.ping.
+type pingResponse struct{}
+
+// workerComm holds pipes and shared memory used for communication
+// between the coordinator process (client) and a worker process (server).
+// These values are unique to each worker; they are shared only with the
+// coordinator, not with other workers.
+//
+// Access to shared memory is synchronized implicitly over the RPC protocol
+// implemented in workerServer and workerClient. During a call, the client
+// (worker) has exclusive access to shared memory; at other times, the server
+// (coordinator) has exclusive access.
+type workerComm struct {
+	fuzzIn, fuzzOut *os.File
+	memMu           chan *sharedMem // mutex guarding shared memory
+}
+
+// workerServer is a minimalist RPC server, run by fuzz worker processes.
+// It allows the coordinator process (using workerClient) to call methods in a
+// worker process. This system allows the coordinator to run multiple worker
+// processes in parallel and to collect inputs that caused crashes from shared
+// memory after a worker process terminates unexpectedly.
+type workerServer struct {
+	workerComm
+	m *mutator
+
+	// coverageMask is the local coverage data for the worker. It is
+	// periodically updated to reflect the data in the coordinator when new
+	// coverage is found.
+	coverageMask []byte
+
+	// fuzzFn runs the worker's fuzz target on the given input and returns an
+	// error if it finds a crasher (the process may also exit or crash), and the
+	// time it took to run the input. It sets a deadline of 10 seconds, at which
+	// point it will panic with the assumption that the process is hanging or
+	// deadlocked.
+	fuzzFn func(CorpusEntry) (time.Duration, error)
+}
+
+// serve reads serialized RPC messages on fuzzIn. When serve receives a message,
+// it calls the corresponding method, then sends the serialized result back
+// on fuzzOut.
+//
+// serve handles RPC calls synchronously; it will not attempt to read a message
+// until the previous call has finished.
+//
+// serve returns errors that occurred when communicating over pipes. serve
+// does not return errors from method calls; those are passed through serialized
+// responses.
+func (ws *workerServer) serve(ctx context.Context) error {
+	enc := json.NewEncoder(ws.fuzzOut)
+	dec := json.NewDecoder(&contextReader{ctx: ctx, r: ws.fuzzIn})
+	for {
+		var c call
+		if err := dec.Decode(&c); err != nil {
+			if err == io.EOF || err == ctx.Err() {
+				return nil
+			} else {
+				return err
+			}
+		}
+
+		var resp any
+		switch {
+		case c.Fuzz != nil:
+			resp = ws.fuzz(ctx, *c.Fuzz)
+		case c.Minimize != nil:
+			resp = ws.minimize(ctx, *c.Minimize)
+		case c.Ping != nil:
+			resp = ws.ping(ctx, *c.Ping)
+		default:
+			return errors.New("no arguments provided for any call")
+		}
+
+		if err := enc.Encode(resp); err != nil {
+			return err
+		}
+	}
+}
+
+// chainedMutations is how many mutations are applied before the worker
+// resets the input to it's original state.
+// NOTE: this number was picked without much thought. It is low enough that
+// it seems to create a significant diversity in mutated inputs. We may want
+// to consider looking into this more closely once we have a proper performance
+// testing framework. Another option is to randomly pick the number of chained
+// mutations on each invocation of the workerServer.fuzz method (this appears to
+// be what libFuzzer does, although there seems to be no documentation which
+// explains why this choice was made.)
+const chainedMutations = 5
+
+// fuzz runs the test function on random variations of the input value in shared
+// memory for a limited duration or number of iterations.
+//
+// fuzz returns early if it finds an input that crashes the fuzz function (with
+// fuzzResponse.Err set) or an input that expands coverage (with
+// fuzzResponse.InterestingDuration set).
+//
+// fuzz does not modify the input in shared memory. Instead, it saves the
+// initial PRNG state in shared memory and increments a counter in shared
+// memory before each call to the test function. The caller may reconstruct
+// the crashing input with this information, since the PRNG is deterministic.
+func (ws *workerServer) fuzz(ctx context.Context, args fuzzArgs) (resp fuzzResponse) {
+	if args.CoverageData != nil {
+		if ws.coverageMask != nil && len(args.CoverageData) != len(ws.coverageMask) {
+			resp.InternalErr = fmt.Sprintf("unexpected size for CoverageData: got %d, expected %d", len(args.CoverageData), len(ws.coverageMask))
+			return resp
+		}
+		ws.coverageMask = args.CoverageData
+	}
+	start := time.Now()
+	defer func() { resp.TotalDuration = time.Since(start) }()
+
+	if args.Timeout != 0 {
+		var cancel func()
+		ctx, cancel = context.WithTimeout(ctx, args.Timeout)
+		defer cancel()
+	}
+	mem := <-ws.memMu
+	ws.m.r.save(&mem.header().randState, &mem.header().randInc)
+	defer func() {
+		resp.Count = mem.header().count
+		ws.memMu <- mem
+	}()
+	if args.Limit > 0 && mem.header().count >= args.Limit {
+		resp.InternalErr = fmt.Sprintf("mem.header().count %d already exceeds args.Limit %d", mem.header().count, args.Limit)
+		return resp
+	}
+
+	originalVals, err := unmarshalCorpusFile(mem.valueCopy())
+	if err != nil {
+		resp.InternalErr = err.Error()
+		return resp
+	}
+	vals := make([]any, len(originalVals))
+	copy(vals, originalVals)
+
+	shouldStop := func() bool {
+		return args.Limit > 0 && mem.header().count >= args.Limit
+	}
+	fuzzOnce := func(entry CorpusEntry) (dur time.Duration, cov []byte, errMsg string) {
+		mem.header().count++
+		var err error
+		dur, err = ws.fuzzFn(entry)
+		if err != nil {
+			errMsg = err.Error()
+			if errMsg == "" {
+				errMsg = "fuzz function failed with no input"
+			}
+			return dur, nil, errMsg
+		}
+		if ws.coverageMask != nil && countNewCoverageBits(ws.coverageMask, coverageSnapshot) > 0 {
+			return dur, coverageSnapshot, ""
+		}
+		return dur, nil, ""
+	}
+
+	if args.Warmup {
+		dur, _, errMsg := fuzzOnce(CorpusEntry{Values: vals})
+		if errMsg != "" {
+			resp.Err = errMsg
+			return resp
+		}
+		resp.InterestingDuration = dur
+		if coverageEnabled {
+			resp.CoverageData = coverageSnapshot
+		}
+		return resp
+	}
+
+	for {
+		select {
+		case <-ctx.Done():
+			return resp
+		default:
+			if mem.header().count%chainedMutations == 0 {
+				copy(vals, originalVals)
+				ws.m.r.save(&mem.header().randState, &mem.header().randInc)
+			}
+			ws.m.mutate(vals, cap(mem.valueRef()))
+
+			entry := CorpusEntry{Values: vals}
+			dur, cov, errMsg := fuzzOnce(entry)
+			if errMsg != "" {
+				resp.Err = errMsg
+				return resp
+			}
+			if cov != nil {
+				resp.CoverageData = cov
+				resp.InterestingDuration = dur
+				return resp
+			}
+			if shouldStop() {
+				return resp
+			}
+		}
+	}
+}
+
+func (ws *workerServer) minimize(ctx context.Context, args minimizeArgs) (resp minimizeResponse) {
+	start := time.Now()
+	defer func() { resp.Duration = time.Since(start) }()
+	mem := <-ws.memMu
+	defer func() { ws.memMu <- mem }()
+	vals, err := unmarshalCorpusFile(mem.valueCopy())
+	if err != nil {
+		panic(err)
+	}
+	inpHash := sha256.Sum256(mem.valueCopy())
+	if args.Timeout != 0 {
+		var cancel func()
+		ctx, cancel = context.WithTimeout(ctx, args.Timeout)
+		defer cancel()
+	}
+
+	// Minimize the values in vals, then write to shared memory. We only write
+	// to shared memory after completing minimization.
+	success, err := ws.minimizeInput(ctx, vals, mem, args)
+	if success {
+		writeToMem(vals, mem)
+		outHash := sha256.Sum256(mem.valueCopy())
+		mem.header().rawInMem = false
+		resp.WroteToMem = true
+		if err != nil {
+			resp.Err = err.Error()
+		} else {
+			// If the values didn't change during minimization then coverageSnapshot is likely
+			// a dirty snapshot which represents the very last step of minimization, not the
+			// coverage for the initial input. In that case just return the coverage we were
+			// given initially, since it more accurately represents the coverage map for the
+			// input we are returning.
+			if outHash != inpHash {
+				resp.CoverageData = coverageSnapshot
+			} else {
+				resp.CoverageData = args.KeepCoverage
+			}
+		}
+	}
+	return resp
+}
+
+// minimizeInput applies a series of minimizing transformations on the provided
+// vals, ensuring that each minimization still causes an error, or keeps
+// coverage, in fuzzFn. It uses the context to determine how long to run,
+// stopping once closed. It returns a bool indicating whether minimization was
+// successful and an error if one was found.
+func (ws *workerServer) minimizeInput(ctx context.Context, vals []any, mem *sharedMem, args minimizeArgs) (success bool, retErr error) {
+	keepCoverage := args.KeepCoverage
+	memBytes := mem.valueRef()
+	bPtr := &memBytes
+	count := &mem.header().count
+	shouldStop := func() bool {
+		return ctx.Err() != nil ||
+			(args.Limit > 0 && *count >= args.Limit)
+	}
+	if shouldStop() {
+		return false, nil
+	}
+
+	// Check that the original value preserves coverage or causes an error.
+	// If not, then whatever caused us to think the value was interesting may
+	// have been a flake, and we can't minimize it.
+	*count++
+	_, retErr = ws.fuzzFn(CorpusEntry{Values: vals})
+	if keepCoverage != nil {
+		if !hasCoverageBit(keepCoverage, coverageSnapshot) || retErr != nil {
+			return false, nil
+		}
+	} else if retErr == nil {
+		return false, nil
+	}
+	mem.header().rawInMem = true
+
+	// tryMinimized runs the fuzz function with candidate replacing the value
+	// at index valI. tryMinimized returns whether the input with candidate is
+	// interesting for the same reason as the original input: it returns
+	// an error if one was expected, or it preserves coverage.
+	tryMinimized := func(candidate []byte) bool {
+		prev := vals[args.Index]
+		switch prev.(type) {
+		case []byte:
+			vals[args.Index] = candidate
+		case string:
+			vals[args.Index] = string(candidate)
+		default:
+			panic("impossible")
+		}
+		copy(*bPtr, candidate)
+		*bPtr = (*bPtr)[:len(candidate)]
+		mem.setValueLen(len(candidate))
+		*count++
+		_, err := ws.fuzzFn(CorpusEntry{Values: vals})
+		if err != nil {
+			retErr = err
+			if keepCoverage != nil {
+				// Now that we've found a crash, that's more important than any
+				// minimization of interesting inputs that was being done. Clear out
+				// keepCoverage to only minimize the crash going forward.
+				keepCoverage = nil
+			}
+			return true
+		}
+		// Minimization should preserve coverage bits.
+		if keepCoverage != nil && isCoverageSubset(keepCoverage, coverageSnapshot) {
+			return true
+		}
+		vals[args.Index] = prev
+		return false
+	}
+	switch v := vals[args.Index].(type) {
+	case string:
+		minimizeBytes([]byte(v), tryMinimized, shouldStop)
+	case []byte:
+		minimizeBytes(v, tryMinimized, shouldStop)
+	default:
+		panic("impossible")
+	}
+	return true, retErr
+}
+
+func writeToMem(vals []any, mem *sharedMem) {
+	b := marshalCorpusFile(vals...)
+	mem.setValue(b)
+}
+
+// ping does nothing. The coordinator calls this method to ensure the worker
+// has called F.Fuzz and can communicate.
+func (ws *workerServer) ping(ctx context.Context, args pingArgs) pingResponse {
+	return pingResponse{}
+}
+
+// workerClient is a minimalist RPC client. The coordinator process uses a
+// workerClient to call methods in each worker process (handled by
+// workerServer).
+type workerClient struct {
+	workerComm
+	m *mutator
+
+	// mu is the mutex protecting the workerComm.fuzzIn pipe. This must be
+	// locked before making calls to the workerServer. It prevents
+	// workerClient.Close from closing fuzzIn while workerClient methods are
+	// writing to it concurrently, and prevents multiple callers from writing to
+	// fuzzIn concurrently.
+	mu sync.Mutex
+}
+
+func newWorkerClient(comm workerComm, m *mutator) *workerClient {
+	return &workerClient{workerComm: comm, m: m}
+}
+
+// Close shuts down the connection to the RPC server (the worker process) by
+// closing fuzz_in. Close drains fuzz_out (avoiding a SIGPIPE in the worker),
+// and closes it after the worker process closes the other end.
+func (wc *workerClient) Close() error {
+	wc.mu.Lock()
+	defer wc.mu.Unlock()
+
+	// Close fuzzIn. This signals to the server that there are no more calls,
+	// and it should exit.
+	if err := wc.fuzzIn.Close(); err != nil {
+		wc.fuzzOut.Close()
+		return err
+	}
+
+	// Drain fuzzOut and close it. When the server exits, the kernel will close
+	// its end of fuzzOut, and we'll get EOF.
+	if _, err := io.Copy(io.Discard, wc.fuzzOut); err != nil {
+		wc.fuzzOut.Close()
+		return err
+	}
+	return wc.fuzzOut.Close()
+}
+
+// errSharedMemClosed is returned by workerClient methods that cannot access
+// shared memory because it was closed and unmapped by another goroutine. That
+// can happen when worker.cleanup is called in the worker goroutine while a
+// workerClient.fuzz call runs concurrently.
+//
+// This error should not be reported. It indicates the operation was
+// interrupted.
+var errSharedMemClosed = errors.New("internal error: shared memory was closed and unmapped")
+
+// minimize tells the worker to call the minimize method. See
+// workerServer.minimize.
+func (wc *workerClient) minimize(ctx context.Context, entryIn CorpusEntry, args minimizeArgs) (entryOut CorpusEntry, resp minimizeResponse, retErr error) {
+	wc.mu.Lock()
+	defer wc.mu.Unlock()
+
+	mem, ok := <-wc.memMu
+	if !ok {
+		return CorpusEntry{}, minimizeResponse{}, errSharedMemClosed
+	}
+	mem.header().count = 0
+	inp, err := corpusEntryData(entryIn)
+	if err != nil {
+		return CorpusEntry{}, minimizeResponse{}, err
+	}
+	mem.setValue(inp)
+	defer func() { wc.memMu <- mem }()
+	entryOut = entryIn
+	entryOut.Values, err = unmarshalCorpusFile(inp)
+	if err != nil {
+		return CorpusEntry{}, minimizeResponse{}, fmt.Errorf("workerClient.minimize unmarshaling provided value: %v", err)
+	}
+	for i, v := range entryOut.Values {
+		if !isMinimizable(reflect.TypeOf(v)) {
+			continue
+		}
+
+		wc.memMu <- mem
+		args.Index = i
+		c := call{Minimize: &args}
+		callErr := wc.callLocked(ctx, c, &resp)
+		mem, ok = <-wc.memMu
+		if !ok {
+			return CorpusEntry{}, minimizeResponse{}, errSharedMemClosed
+		}
+
+		if callErr != nil {
+			retErr = callErr
+			if !mem.header().rawInMem {
+				// An unrecoverable error occurred before minimization began.
+				return entryIn, minimizeResponse{}, retErr
+			}
+			// An unrecoverable error occurred during minimization. mem now
+			// holds the raw, unmarshalled bytes of entryIn.Values[i] that
+			// caused the error.
+			switch entryOut.Values[i].(type) {
+			case string:
+				entryOut.Values[i] = string(mem.valueCopy())
+			case []byte:
+				entryOut.Values[i] = mem.valueCopy()
+			default:
+				panic("impossible")
+			}
+			entryOut.Data = marshalCorpusFile(entryOut.Values...)
+			// Stop minimizing; another unrecoverable error is likely to occur.
+			break
+		}
+
+		if resp.WroteToMem {
+			// Minimization succeeded, and mem holds the marshaled data.
+			entryOut.Data = mem.valueCopy()
+			entryOut.Values, err = unmarshalCorpusFile(entryOut.Data)
+			if err != nil {
+				return CorpusEntry{}, minimizeResponse{}, fmt.Errorf("workerClient.minimize unmarshaling minimized value: %v", err)
+			}
+		}
+
+		// Prepare for next iteration of the loop.
+		if args.Timeout != 0 {
+			args.Timeout -= resp.Duration
+			if args.Timeout <= 0 {
+				break
+			}
+		}
+		if args.Limit != 0 {
+			args.Limit -= mem.header().count
+			if args.Limit <= 0 {
+				break
+			}
+		}
+	}
+	resp.Count = mem.header().count
+	h := sha256.Sum256(entryOut.Data)
+	entryOut.Path = fmt.Sprintf("%x", h[:4])
+	return entryOut, resp, retErr
+}
+
+// fuzz tells the worker to call the fuzz method. See workerServer.fuzz.
+func (wc *workerClient) fuzz(ctx context.Context, entryIn CorpusEntry, args fuzzArgs) (entryOut CorpusEntry, resp fuzzResponse, isInternalError bool, err error) {
+	wc.mu.Lock()
+	defer wc.mu.Unlock()
+
+	mem, ok := <-wc.memMu
+	if !ok {
+		return CorpusEntry{}, fuzzResponse{}, true, errSharedMemClosed
+	}
+	mem.header().count = 0
+	inp, err := corpusEntryData(entryIn)
+	if err != nil {
+		return CorpusEntry{}, fuzzResponse{}, true, err
+	}
+	mem.setValue(inp)
+	wc.memMu <- mem
+
+	c := call{Fuzz: &args}
+	callErr := wc.callLocked(ctx, c, &resp)
+	if resp.InternalErr != "" {
+		return CorpusEntry{}, fuzzResponse{}, true, errors.New(resp.InternalErr)
+	}
+	mem, ok = <-wc.memMu
+	if !ok {
+		return CorpusEntry{}, fuzzResponse{}, true, errSharedMemClosed
+	}
+	defer func() { wc.memMu <- mem }()
+	resp.Count = mem.header().count
+
+	if !bytes.Equal(inp, mem.valueRef()) {
+		return CorpusEntry{}, fuzzResponse{}, true, errors.New("workerServer.fuzz modified input")
+	}
+	needEntryOut := callErr != nil || resp.Err != "" ||
+		(!args.Warmup && resp.CoverageData != nil)
+	if needEntryOut {
+		valuesOut, err := unmarshalCorpusFile(inp)
+		if err != nil {
+			return CorpusEntry{}, fuzzResponse{}, true, fmt.Errorf("unmarshaling fuzz input value after call: %v", err)
+		}
+		wc.m.r.restore(mem.header().randState, mem.header().randInc)
+		if !args.Warmup {
+			// Only mutate the valuesOut if fuzzing actually occurred.
+			numMutations := ((resp.Count - 1) % chainedMutations) + 1
+			for i := int64(0); i < numMutations; i++ {
+				wc.m.mutate(valuesOut, cap(mem.valueRef()))
+			}
+		}
+		dataOut := marshalCorpusFile(valuesOut...)
+
+		h := sha256.Sum256(dataOut)
+		name := fmt.Sprintf("%x", h[:4])
+		entryOut = CorpusEntry{
+			Parent:     entryIn.Path,
+			Path:       name,
+			Data:       dataOut,
+			Generation: entryIn.Generation + 1,
+		}
+		if args.Warmup {
+			// The bytes weren't mutated, so if entryIn was a seed corpus value,
+			// then entryOut is too.
+			entryOut.IsSeed = entryIn.IsSeed
+		}
+	}
+
+	return entryOut, resp, false, callErr
+}
+
+// ping tells the worker to call the ping method. See workerServer.ping.
+func (wc *workerClient) ping(ctx context.Context) error {
+	wc.mu.Lock()
+	defer wc.mu.Unlock()
+	c := call{Ping: &pingArgs{}}
+	var resp pingResponse
+	return wc.callLocked(ctx, c, &resp)
+}
+
+// callLocked sends an RPC from the coordinator to the worker process and waits
+// for the response. The callLocked may be cancelled with ctx.
+func (wc *workerClient) callLocked(ctx context.Context, c call, resp any) (err error) {
+	enc := json.NewEncoder(wc.fuzzIn)
+	dec := json.NewDecoder(&contextReader{ctx: ctx, r: wc.fuzzOut})
+	if err := enc.Encode(c); err != nil {
+		return err
+	}
+	return dec.Decode(resp)
+}
+
+// contextReader wraps a Reader with a Context. If the context is cancelled
+// while the underlying reader is blocked, Read returns immediately.
+//
+// This is useful for reading from a pipe. Closing a pipe file descriptor does
+// not unblock pending Reads on that file descriptor. All copies of the pipe's
+// other file descriptor (the write end) must be closed in all processes that
+// inherit it. This is difficult to do correctly in the situation we care about
+// (process group termination).
+type contextReader struct {
+	ctx context.Context
+	r   io.Reader
+}
+
+func (cr *contextReader) Read(b []byte) (int, error) {
+	if ctxErr := cr.ctx.Err(); ctxErr != nil {
+		return 0, ctxErr
+	}
+	done := make(chan struct{})
+
+	// This goroutine may stay blocked after Read returns because the underlying
+	// read is blocked.
+	var n int
+	var err error
+	go func() {
+		n, err = cr.r.Read(b)
+		close(done)
+	}()
+
+	select {
+	case <-cr.ctx.Done():
+		return 0, cr.ctx.Err()
+	case <-done:
+		return n, err
+	}
+}
diff --git a/contrib/go/_std_1.20/src/internal/fuzz/ya.make b/contrib/go/_std_1.20/src/internal/fuzz/ya.make
new file mode 100644
index 0000000000..6643d232bb
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/fuzz/ya.make
@@ -0,0 +1,36 @@
+GO_LIBRARY()
+
+SRCS(
+    counters_supported.go
+    coverage.go
+    encoding.go
+    fuzz.go
+    mem.go
+    minimize.go
+    mutator.go
+    mutators_byteslice.go
+    pcg.go
+    queue.go
+    trace.go
+    worker.go
+)
+
+IF (OS_DARWIN)
+    SRCS(
+        sys_posix.go
+    )
+ENDIF()
+
+IF (OS_LINUX)
+    SRCS(
+        sys_posix.go
+    )
+ENDIF()
+
+IF (OS_WINDOWS)
+    SRCS(
+        sys_windows.go
+    )
+ENDIF()
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/goarch/goarch.go b/contrib/go/_std_1.20/src/internal/goarch/goarch.go
new file mode 100644
index 0000000000..3dda62fadc
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goarch/goarch.go
@@ -0,0 +1,60 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// package goarch contains GOARCH-specific constants.
+package goarch
+
+// The next line makes 'go generate' write the zgoarch*.go files with
+// per-arch information, including constants named $GOARCH for every
+// GOARCH. The constant is 1 on the current system, 0 otherwise; multiplying
+// by them is useful for defining GOARCH-specific constants.
+//
+//go:generate go run gengoarch.go
+
+type ArchFamilyType int
+
+const (
+	AMD64 ArchFamilyType = iota
+	ARM
+	ARM64
+	I386
+	LOONG64
+	MIPS
+	MIPS64
+	PPC64
+	RISCV64
+	S390X
+	WASM
+)
+
+// PtrSize is the size of a pointer in bytes - unsafe.Sizeof(uintptr(0)) but as an ideal constant.
+// It is also the size of the machine's native word size (that is, 4 on 32-bit systems, 8 on 64-bit).
+const PtrSize = 4 << (^uintptr(0) >> 63)
+
+// ArchFamily is the architecture family (AMD64, ARM, ...)
+const ArchFamily ArchFamilyType = _ArchFamily
+
+// BigEndian reports whether the architecture is big-endian.
+const BigEndian = IsArmbe|IsArm64be|IsMips|IsMips64|IsPpc|IsPpc64|IsS390|IsS390x|IsSparc|IsSparc64 == 1
+
+// DefaultPhysPageSize is the default physical page size.
+const DefaultPhysPageSize = _DefaultPhysPageSize
+
+// PCQuantum is the minimal unit for a program counter (1 on x86, 4 on most other systems).
+// The various PC tables record PC deltas pre-divided by PCQuantum.
+const PCQuantum = _PCQuantum
+
+// Int64Align is the required alignment for a 64-bit integer (4 on 32-bit systems, 8 on 64-bit).
+const Int64Align = PtrSize
+
+// MinFrameSize is the size of the system-reserved words at the bottom
+// of a frame (just above the architectural stack pointer).
+// It is zero on x86 and PtrSize on most non-x86 (LR-based) systems.
+// On PowerPC it is larger, to cover three more reserved words:
+// the compiler word, the link editor word, and the TOC save word.
+const MinFrameSize = _MinFrameSize
+
+// StackAlign is the required alignment of the SP register.
+// The stack must be at least word aligned, but some architectures require more.
+const StackAlign = _StackAlign
diff --git a/contrib/go/_std_1.20/src/internal/goarch/goarch_amd64.go b/contrib/go/_std_1.20/src/internal/goarch/goarch_amd64.go
new file mode 100644
index 0000000000..911e3e7242
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goarch/goarch_amd64.go
@@ -0,0 +1,13 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package goarch
+
+const (
+	_ArchFamily          = AMD64
+	_DefaultPhysPageSize = 4096
+	_PCQuantum           = 1
+	_MinFrameSize        = 0
+	_StackAlign          = PtrSize
+)
diff --git a/contrib/go/_std_1.20/src/internal/goarch/goarch_arm64.go b/contrib/go/_std_1.20/src/internal/goarch/goarch_arm64.go
new file mode 100644
index 0000000000..85d0b47639
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goarch/goarch_arm64.go
@@ -0,0 +1,13 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package goarch
+
+const (
+	_ArchFamily          = ARM64
+	_DefaultPhysPageSize = 65536
+	_PCQuantum           = 4
+	_MinFrameSize        = 8
+	_StackAlign          = 16
+)
diff --git a/contrib/go/_std_1.20/src/internal/goarch/ya.make b/contrib/go/_std_1.20/src/internal/goarch/ya.make
new file mode 100644
index 0000000000..8483e0734e
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goarch/ya.make
@@ -0,0 +1,21 @@
+GO_LIBRARY()
+
+SRCS(
+    goarch.go
+)
+
+IF (ARCH_ARM64)
+    SRCS(
+        goarch_arm64.go
+        zgoarch_arm64.go
+    )
+ENDIF()
+
+IF (ARCH_X86_64)
+    SRCS(
+        goarch_amd64.go
+        zgoarch_amd64.go
+    )
+ENDIF()
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/goarch/zgoarch_amd64.go b/contrib/go/_std_1.20/src/internal/goarch/zgoarch_amd64.go
new file mode 100644
index 0000000000..7926392b77
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goarch/zgoarch_amd64.go
@@ -0,0 +1,32 @@
+// Code generated by gengoarch.go using 'go generate'. DO NOT EDIT.
+
+//go:build amd64
+
+package goarch
+
+const GOARCH = `amd64`
+
+const Is386 = 0
+const IsAmd64 = 1
+const IsAmd64p32 = 0
+const IsArm = 0
+const IsArmbe = 0
+const IsArm64 = 0
+const IsArm64be = 0
+const IsLoong64 = 0
+const IsMips = 0
+const IsMipsle = 0
+const IsMips64 = 0
+const IsMips64le = 0
+const IsMips64p32 = 0
+const IsMips64p32le = 0
+const IsPpc = 0
+const IsPpc64 = 0
+const IsPpc64le = 0
+const IsRiscv = 0
+const IsRiscv64 = 0
+const IsS390 = 0
+const IsS390x = 0
+const IsSparc = 0
+const IsSparc64 = 0
+const IsWasm = 0
diff --git a/contrib/go/_std_1.20/src/internal/goarch/zgoarch_arm64.go b/contrib/go/_std_1.20/src/internal/goarch/zgoarch_arm64.go
new file mode 100644
index 0000000000..ad342d79c9
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goarch/zgoarch_arm64.go
@@ -0,0 +1,32 @@
+// Code generated by gengoarch.go using 'go generate'. DO NOT EDIT.
+
+//go:build arm64
+
+package goarch
+
+const GOARCH = `arm64`
+
+const Is386 = 0
+const IsAmd64 = 0
+const IsAmd64p32 = 0
+const IsArm = 0
+const IsArmbe = 0
+const IsArm64 = 1
+const IsArm64be = 0
+const IsLoong64 = 0
+const IsMips = 0
+const IsMipsle = 0
+const IsMips64 = 0
+const IsMips64le = 0
+const IsMips64p32 = 0
+const IsMips64p32le = 0
+const IsPpc = 0
+const IsPpc64 = 0
+const IsPpc64le = 0
+const IsRiscv = 0
+const IsRiscv64 = 0
+const IsS390 = 0
+const IsS390x = 0
+const IsSparc = 0
+const IsSparc64 = 0
+const IsWasm = 0
diff --git a/contrib/go/_std_1.20/src/internal/godebug/godebug.go b/contrib/go/_std_1.20/src/internal/godebug/godebug.go
new file mode 100644
index 0000000000..26f360c73c
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/godebug/godebug.go
@@ -0,0 +1,165 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package godebug makes the settings in the $GODEBUG environment variable
+// available to other packages. These settings are often used for compatibility
+// tweaks, when we need to change a default behavior but want to let users
+// opt back in to the original. For example GODEBUG=http2server=0 disables
+// HTTP/2 support in the net/http server.
+//
+// In typical usage, code should declare a Setting as a global
+// and then call Value each time the current setting value is needed:
+//
+//	var http2server = godebug.New("http2server")
+//
+//	func ServeConn(c net.Conn) {
+//		if http2server.Value() == "0" {
+//			disallow HTTP/2
+//			...
+//		}
+//		...
+//	}
+package godebug
+
+import (
+	"sync"
+	"sync/atomic"
+	_ "unsafe" // go:linkname
+
+)
+
+// A Setting is a single setting in the $GODEBUG environment variable.
+type Setting struct {
+	name  string
+	once  sync.Once
+	value *atomic.Pointer[string]
+}
+
+// New returns a new Setting for the $GODEBUG setting with the given name.
+func New(name string) *Setting {
+	return &Setting{name: name}
+}
+
+// Name returns the name of the setting.
+func (s *Setting) Name() string {
+	return s.name
+}
+
+// String returns a printable form for the setting: name=value.
+func (s *Setting) String() string {
+	return s.name + "=" + s.Value()
+}
+
+// cache is a cache of all the GODEBUG settings,
+// a locked map[string]*atomic.Pointer[string].
+//
+// All Settings with the same name share a single
+// *atomic.Pointer[string], so that when GODEBUG
+// changes only that single atomic string pointer
+// needs to be updated.
+//
+// A name appears in the values map either if it is the
+// name of a Setting for which Value has been called
+// at least once, or if the name has ever appeared in
+// a name=value pair in the $GODEBUG environment variable.
+// Once entered into the map, the name is never removed.
+var cache sync.Map // name string -> value *atomic.Pointer[string]
+
+var empty string
+
+// Value returns the current value for the GODEBUG setting s.
+//
+// Value maintains an internal cache that is synchronized
+// with changes to the $GODEBUG environment variable,
+// making Value efficient to call as frequently as needed.
+// Clients should therefore typically not attempt their own
+// caching of Value's result.
+func (s *Setting) Value() string {
+	s.once.Do(func() {
+		v, ok := cache.Load(s.name)
+		if !ok {
+			p := new(atomic.Pointer[string])
+			p.Store(&empty)
+			v, _ = cache.LoadOrStore(s.name, p)
+		}
+		s.value = v.(*atomic.Pointer[string])
+	})
+	return *s.value.Load()
+}
+
+// setUpdate is provided by package runtime.
+// It calls update(def, env), where def is the default GODEBUG setting
+// and env is the current value of the $GODEBUG environment variable.
+// After that first call, the runtime calls update(def, env)
+// again each time the environment variable changes
+// (due to use of os.Setenv, for example).
+//
+//go:linkname setUpdate
+func setUpdate(update func(string, string))
+
+func init() {
+	setUpdate(update)
+}
+
+var updateMu sync.Mutex
+
+// update records an updated GODEBUG setting.
+// def is the default GODEBUG setting for the running binary,
+// and env is the current value of the $GODEBUG environment variable.
+func update(def, env string) {
+	updateMu.Lock()
+	defer updateMu.Unlock()
+
+	// Update all the cached values, creating new ones as needed.
+	// We parse the environment variable first, so that any settings it has
+	// are already locked in place (did[name] = true) before we consider
+	// the defaults.
+	did := make(map[string]bool)
+	parse(did, env)
+	parse(did, def)
+
+	// Clear any cached values that are no longer present.
+	cache.Range(func(name, v any) bool {
+		if !did[name.(string)] {
+			v.(*atomic.Pointer[string]).Store(&empty)
+		}
+		return true
+	})
+}
+
+// parse parses the GODEBUG setting string s,
+// which has the form k=v,k2=v2,k3=v3.
+// Later settings override earlier ones.
+// Parse only updates settings k=v for which did[k] = false.
+// It also sets did[k] = true for settings that it updates.
+func parse(did map[string]bool, s string) {
+	// Scan the string backward so that later settings are used
+	// and earlier settings are ignored.
+	// Note that a forward scan would cause cached values
+	// to temporarily use the ignored value before being
+	// updated to the "correct" one.
+	end := len(s)
+	eq := -1
+	for i := end - 1; i >= -1; i-- {
+		if i == -1 || s[i] == ',' {
+			if eq >= 0 {
+				name, value := s[i+1:eq], s[eq+1:end]
+				if !did[name] {
+					did[name] = true
+					v, ok := cache.Load(name)
+					if !ok {
+						p := new(atomic.Pointer[string])
+						p.Store(&empty)
+						v, _ = cache.LoadOrStore(name, p)
+					}
+					v.(*atomic.Pointer[string]).Store(&value)
+				}
+			}
+			eq = -1
+			end = i
+		} else if s[i] == '=' {
+			eq = i
+		}
+	}
+}
diff --git a/contrib/go/_std_1.20/src/internal/godebug/ya.make b/contrib/go/_std_1.20/src/internal/godebug/ya.make
new file mode 100644
index 0000000000..aeb5fa5afc
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/godebug/ya.make
@@ -0,0 +1,7 @@
+GO_LIBRARY()
+
+SRCS(
+    godebug.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/goexperiment/exp_arenas_off.go b/contrib/go/_std_1.20/src/internal/goexperiment/exp_arenas_off.go
new file mode 100644
index 0000000000..9e40ebc37b
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goexperiment/exp_arenas_off.go
@@ -0,0 +1,9 @@
+// Code generated by mkconsts.go. DO NOT EDIT.
+
+//go:build !goexperiment.arenas
+// +build !goexperiment.arenas
+
+package goexperiment
+
+const Arenas = false
+const ArenasInt = 0
diff --git a/contrib/go/_std_1.20/src/internal/goexperiment/exp_boringcrypto_off.go b/contrib/go/_std_1.20/src/internal/goexperiment/exp_boringcrypto_off.go
new file mode 100644
index 0000000000..020c75bd53
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goexperiment/exp_boringcrypto_off.go
@@ -0,0 +1,9 @@
+// Code generated by mkconsts.go. DO NOT EDIT.
+
+//go:build !goexperiment.boringcrypto
+// +build !goexperiment.boringcrypto
+
+package goexperiment
+
+const BoringCrypto = false
+const BoringCryptoInt = 0
diff --git a/contrib/go/_std_1.20/src/internal/goexperiment/exp_coverageredesign_off.go b/contrib/go/_std_1.20/src/internal/goexperiment/exp_coverageredesign_off.go
new file mode 100644
index 0000000000..95d3a6c4ae
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goexperiment/exp_coverageredesign_off.go
@@ -0,0 +1,9 @@
+// Code generated by mkconsts.go. DO NOT EDIT.
+
+//go:build !goexperiment.coverageredesign
+// +build !goexperiment.coverageredesign
+
+package goexperiment
+
+const CoverageRedesign = false
+const CoverageRedesignInt = 0
diff --git a/contrib/go/_std_1.20/src/internal/goexperiment/exp_fieldtrack_off.go b/contrib/go/_std_1.20/src/internal/goexperiment/exp_fieldtrack_off.go
new file mode 100644
index 0000000000..e5e132660e
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goexperiment/exp_fieldtrack_off.go
@@ -0,0 +1,9 @@
+// Code generated by mkconsts.go. DO NOT EDIT.
+
+//go:build !goexperiment.fieldtrack
+// +build !goexperiment.fieldtrack
+
+package goexperiment
+
+const FieldTrack = false
+const FieldTrackInt = 0
diff --git a/contrib/go/_std_1.20/src/internal/goexperiment/exp_heapminimum512kib_off.go b/contrib/go/_std_1.20/src/internal/goexperiment/exp_heapminimum512kib_off.go
new file mode 100644
index 0000000000..09da431b40
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goexperiment/exp_heapminimum512kib_off.go
@@ -0,0 +1,9 @@
+// Code generated by mkconsts.go. DO NOT EDIT.
+
+//go:build !goexperiment.heapminimum512kib
+// +build !goexperiment.heapminimum512kib
+
+package goexperiment
+
+const HeapMinimum512KiB = false
+const HeapMinimum512KiBInt = 0
diff --git a/contrib/go/_std_1.20/src/internal/goexperiment/exp_pagetrace_off.go b/contrib/go/_std_1.20/src/internal/goexperiment/exp_pagetrace_off.go
new file mode 100644
index 0000000000..789e88332d
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goexperiment/exp_pagetrace_off.go
@@ -0,0 +1,9 @@
+// Code generated by mkconsts.go. DO NOT EDIT.
+
+//go:build !goexperiment.pagetrace
+// +build !goexperiment.pagetrace
+
+package goexperiment
+
+const PageTrace = false
+const PageTraceInt = 0
diff --git a/contrib/go/_std_1.20/src/internal/goexperiment/exp_preemptibleloops_off.go b/contrib/go/_std_1.20/src/internal/goexperiment/exp_preemptibleloops_off.go
new file mode 100644
index 0000000000..7a26088e80
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goexperiment/exp_preemptibleloops_off.go
@@ -0,0 +1,9 @@
+// Code generated by mkconsts.go. DO NOT EDIT.
+
+//go:build !goexperiment.preemptibleloops
+// +build !goexperiment.preemptibleloops
+
+package goexperiment
+
+const PreemptibleLoops = false
+const PreemptibleLoopsInt = 0
diff --git a/contrib/go/_std_1.20/src/internal/goexperiment/exp_regabiargs_on.go b/contrib/go/_std_1.20/src/internal/goexperiment/exp_regabiargs_on.go
new file mode 100644
index 0000000000..9b26f3c9cb
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goexperiment/exp_regabiargs_on.go
@@ -0,0 +1,9 @@
+// Code generated by mkconsts.go. DO NOT EDIT.
+
+//go:build goexperiment.regabiargs
+// +build goexperiment.regabiargs
+
+package goexperiment
+
+const RegabiArgs = true
+const RegabiArgsInt = 1
diff --git a/contrib/go/_std_1.20/src/internal/goexperiment/exp_regabiwrappers_on.go b/contrib/go/_std_1.20/src/internal/goexperiment/exp_regabiwrappers_on.go
new file mode 100644
index 0000000000..11ffffbbff
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goexperiment/exp_regabiwrappers_on.go
@@ -0,0 +1,9 @@
+// Code generated by mkconsts.go. DO NOT EDIT.
+
+//go:build goexperiment.regabiwrappers
+// +build goexperiment.regabiwrappers
+
+package goexperiment
+
+const RegabiWrappers = true
+const RegabiWrappersInt = 1
diff --git a/contrib/go/_std_1.20/src/internal/goexperiment/exp_staticlockranking_off.go b/contrib/go/_std_1.20/src/internal/goexperiment/exp_staticlockranking_off.go
new file mode 100644
index 0000000000..3d546c04b4
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goexperiment/exp_staticlockranking_off.go
@@ -0,0 +1,9 @@
+// Code generated by mkconsts.go. DO NOT EDIT.
+
+//go:build !goexperiment.staticlockranking
+// +build !goexperiment.staticlockranking
+
+package goexperiment
+
+const StaticLockRanking = false
+const StaticLockRankingInt = 0
diff --git a/contrib/go/_std_1.20/src/internal/goexperiment/exp_unified_off.go b/contrib/go/_std_1.20/src/internal/goexperiment/exp_unified_off.go
new file mode 100644
index 0000000000..4c16fd8562
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goexperiment/exp_unified_off.go
@@ -0,0 +1,9 @@
+// Code generated by mkconsts.go. DO NOT EDIT.
+
+//go:build !goexperiment.unified
+// +build !goexperiment.unified
+
+package goexperiment
+
+const Unified = false
+const UnifiedInt = 0
diff --git a/contrib/go/_std_1.20/src/internal/goexperiment/flags.go b/contrib/go/_std_1.20/src/internal/goexperiment/flags.go
new file mode 100644
index 0000000000..02e744362c
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goexperiment/flags.go
@@ -0,0 +1,103 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package goexperiment implements support for toolchain experiments.
+//
+// Toolchain experiments are controlled by the GOEXPERIMENT
+// environment variable. GOEXPERIMENT is a comma-separated list of
+// experiment names. GOEXPERIMENT can be set at make.bash time, which
+// sets the default experiments for binaries built with the tool
+// chain; or it can be set at build time. GOEXPERIMENT can also be set
+// to "none", which disables any experiments that were enabled at
+// make.bash time.
+//
+// Experiments are exposed to the build in the following ways:
+//
+// - Build tag goexperiment.x is set if experiment x (lower case) is
+// enabled.
+//
+// - For each experiment x (in camel case), this package contains a
+// boolean constant x and an integer constant xInt.
+//
+// - In runtime assembly, the macro GOEXPERIMENT_x is defined if
+// experiment x (lower case) is enabled.
+//
+// In the toolchain, the set of experiments enabled for the current
+// build should be accessed via objabi.Experiment.
+//
+// The set of experiments is included in the output of runtime.Version()
+// and "go version <binary>" if it differs from the default experiments.
+//
+// For the set of experiments supported by the current toolchain, see
+// "go doc goexperiment.Flags".
+//
+// Note that this package defines the set of experiments (in Flags)
+// and records the experiments that were enabled when the package
+// was compiled (as boolean and integer constants).
+//
+// Note especially that this package does not itself change behavior
+// at run time based on the GOEXPERIMENT variable.
+// The code used in builds to interpret the GOEXPERIMENT variable
+// is in the separate package internal/buildcfg.
+package goexperiment
+
+//go:generate go run mkconsts.go
+
+// Flags is the set of experiments that can be enabled or disabled in
+// the current toolchain.
+//
+// When specified in the GOEXPERIMENT environment variable or as build
+// tags, experiments use the strings.ToLower of their field name.
+//
+// For the baseline experimental configuration, see
+// objabi.experimentBaseline.
+//
+// If you change this struct definition, run "go generate".
+type Flags struct {
+	FieldTrack        bool
+	PreemptibleLoops  bool
+	StaticLockRanking bool
+	BoringCrypto      bool
+
+	// Unified enables the compiler's unified IR construction
+	// experiment.
+	Unified bool
+
+	// Regabi is split into several sub-experiments that can be
+	// enabled individually. Not all combinations work.
+	// The "regabi" GOEXPERIMENT is an alias for all "working"
+	// subexperiments.
+
+	// RegabiWrappers enables ABI wrappers for calling between
+	// ABI0 and ABIInternal functions. Without this, the ABIs are
+	// assumed to be identical so cross-ABI calls are direct.
+	RegabiWrappers bool
+	// RegabiArgs enables register arguments/results in all
+	// compiled Go functions.
+	//
+	// Requires wrappers (to do ABI translation), and reflect (so
+	// reflection calls use registers).
+	RegabiArgs bool
+
+	// HeapMinimum512KiB reduces the minimum heap size to 512 KiB.
+	//
+	// This was originally reduced as part of PacerRedesign, but
+	// has been broken out to its own experiment that is disabled
+	// by default.
+	HeapMinimum512KiB bool
+
+	// CoverageRedesign enables the new compiler-based code coverage
+	// tooling.
+	CoverageRedesign bool
+
+	// Arenas causes the "arena" standard library package to be visible
+	// to the outside world.
+	Arenas bool
+
+	// PageTrace enables GODEBUG=pagetrace=/path/to/result. This feature
+	// is a GOEXPERIMENT due to a security risk with setuid binaries:
+	// this compels the Go runtime to write to some arbitrary file, which
+	// may be exploited.
+	PageTrace bool
+}
diff --git a/contrib/go/_std_1.20/src/internal/goexperiment/ya.make b/contrib/go/_std_1.20/src/internal/goexperiment/ya.make
new file mode 100644
index 0000000000..32c0113b21
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goexperiment/ya.make
@@ -0,0 +1,18 @@
+GO_LIBRARY()
+
+SRCS(
+    exp_arenas_off.go
+    exp_boringcrypto_off.go
+    exp_coverageredesign_off.go
+    exp_fieldtrack_off.go
+    exp_heapminimum512kib_off.go
+    exp_pagetrace_off.go
+    exp_preemptibleloops_off.go
+    exp_regabiargs_on.go
+    exp_regabiwrappers_on.go
+    exp_staticlockranking_off.go
+    exp_unified_off.go
+    flags.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/goos/goos.go b/contrib/go/_std_1.20/src/internal/goos/goos.go
new file mode 100644
index 0000000000..02dc9688cb
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goos/goos.go
@@ -0,0 +1,13 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// package goos contains GOOS-specific constants.
+package goos
+
+// The next line makes 'go generate' write the zgoos*.go files with
+// per-OS information, including constants named Is$GOOS for every
+// known GOOS. The constant is 1 on the current system, 0 otherwise;
+// multiplying by them is useful for defining GOOS-specific constants.
+//
+//go:generate go run gengoos.go
diff --git a/contrib/go/_std_1.20/src/internal/goos/nonunix.go b/contrib/go/_std_1.20/src/internal/goos/nonunix.go
new file mode 100644
index 0000000000..2ba5c8555a
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goos/nonunix.go
@@ -0,0 +1,9 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !unix
+
+package goos
+
+const IsUnix = false
diff --git a/contrib/go/_std_1.20/src/internal/goos/unix.go b/contrib/go/_std_1.20/src/internal/goos/unix.go
new file mode 100644
index 0000000000..6cfd5ef675
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goos/unix.go
@@ -0,0 +1,9 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build unix
+
+package goos
+
+const IsUnix = true
diff --git a/contrib/go/_std_1.20/src/internal/goos/ya.make b/contrib/go/_std_1.20/src/internal/goos/ya.make
new file mode 100644
index 0000000000..904eeb29f1
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goos/ya.make
@@ -0,0 +1,28 @@
+GO_LIBRARY()
+
+SRCS(
+    goos.go
+)
+
+IF (OS_DARWIN)
+    SRCS(
+        unix.go
+        zgoos_darwin.go
+    )
+ENDIF()
+
+IF (OS_LINUX)
+    SRCS(
+        unix.go
+        zgoos_linux.go
+    )
+ENDIF()
+
+IF (OS_WINDOWS)
+    SRCS(
+        nonunix.go
+        zgoos_windows.go
+    )
+ENDIF()
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/goos/zgoos_darwin.go b/contrib/go/_std_1.20/src/internal/goos/zgoos_darwin.go
new file mode 100644
index 0000000000..decdd49642
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goos/zgoos_darwin.go
@@ -0,0 +1,25 @@
+// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
+
+//go:build !ios && darwin
+
+package goos
+
+const GOOS = `darwin`
+
+const IsAix = 0
+const IsAndroid = 0
+const IsDarwin = 1
+const IsDragonfly = 0
+const IsFreebsd = 0
+const IsHurd = 0
+const IsIllumos = 0
+const IsIos = 0
+const IsJs = 0
+const IsLinux = 0
+const IsNacl = 0
+const IsNetbsd = 0
+const IsOpenbsd = 0
+const IsPlan9 = 0
+const IsSolaris = 0
+const IsWindows = 0
+const IsZos = 0
diff --git a/contrib/go/_std_1.20/src/internal/goos/zgoos_linux.go b/contrib/go/_std_1.20/src/internal/goos/zgoos_linux.go
new file mode 100644
index 0000000000..cb9d6e8afa
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goos/zgoos_linux.go
@@ -0,0 +1,25 @@
+// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
+
+//go:build !android && linux
+
+package goos
+
+const GOOS = `linux`
+
+const IsAix = 0
+const IsAndroid = 0
+const IsDarwin = 0
+const IsDragonfly = 0
+const IsFreebsd = 0
+const IsHurd = 0
+const IsIllumos = 0
+const IsIos = 0
+const IsJs = 0
+const IsLinux = 1
+const IsNacl = 0
+const IsNetbsd = 0
+const IsOpenbsd = 0
+const IsPlan9 = 0
+const IsSolaris = 0
+const IsWindows = 0
+const IsZos = 0
diff --git a/contrib/go/_std_1.20/src/internal/goos/zgoos_windows.go b/contrib/go/_std_1.20/src/internal/goos/zgoos_windows.go
new file mode 100644
index 0000000000..16158be78b
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goos/zgoos_windows.go
@@ -0,0 +1,25 @@
+// Code generated by gengoos.go using 'go generate'. DO NOT EDIT.
+
+//go:build windows
+
+package goos
+
+const GOOS = `windows`
+
+const IsAix = 0
+const IsAndroid = 0
+const IsDarwin = 0
+const IsDragonfly = 0
+const IsFreebsd = 0
+const IsHurd = 0
+const IsIllumos = 0
+const IsIos = 0
+const IsJs = 0
+const IsLinux = 0
+const IsNacl = 0
+const IsNetbsd = 0
+const IsOpenbsd = 0
+const IsPlan9 = 0
+const IsSolaris = 0
+const IsWindows = 1
+const IsZos = 0
diff --git a/contrib/go/_std_1.20/src/internal/goroot/gc.go b/contrib/go/_std_1.20/src/internal/goroot/gc.go
new file mode 100644
index 0000000000..79403d29fc
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goroot/gc.go
@@ -0,0 +1,131 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build gc
+
+package goroot
+
+import (
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"sync"
+)
+
+// IsStandardPackage reports whether path is a standard package,
+// given goroot and compiler.
+func IsStandardPackage(goroot, compiler, path string) bool {
+	switch compiler {
+	case "gc":
+		dir := filepath.Join(goroot, "src", path)
+		_, err := os.Stat(dir)
+		return err == nil
+	case "gccgo":
+		return gccgoSearch.isStandard(path)
+	default:
+		panic("unknown compiler " + compiler)
+	}
+}
+
+// gccgoSearch holds the gccgo search directories.
+type gccgoDirs struct {
+	once sync.Once
+	dirs []string
+}
+
+// gccgoSearch is used to check whether a gccgo package exists in the
+// standard library.
+var gccgoSearch gccgoDirs
+
+// init finds the gccgo search directories. If this fails it leaves dirs == nil.
+func (gd *gccgoDirs) init() {
+	gccgo := os.Getenv("GCCGO")
+	if gccgo == "" {
+		gccgo = "gccgo"
+	}
+	bin, err := exec.LookPath(gccgo)
+	if err != nil {
+		return
+	}
+
+	allDirs, err := exec.Command(bin, "-print-search-dirs").Output()
+	if err != nil {
+		return
+	}
+	versionB, err := exec.Command(bin, "-dumpversion").Output()
+	if err != nil {
+		return
+	}
+	version := strings.TrimSpace(string(versionB))
+	machineB, err := exec.Command(bin, "-dumpmachine").Output()
+	if err != nil {
+		return
+	}
+	machine := strings.TrimSpace(string(machineB))
+
+	dirsEntries := strings.Split(string(allDirs), "\n")
+	const prefix = "libraries: ="
+	var dirs []string
+	for _, dirEntry := range dirsEntries {
+		if strings.HasPrefix(dirEntry, prefix) {
+			dirs = filepath.SplitList(strings.TrimPrefix(dirEntry, prefix))
+			break
+		}
+	}
+	if len(dirs) == 0 {
+		return
+	}
+
+	var lastDirs []string
+	for _, dir := range dirs {
+		goDir := filepath.Join(dir, "go", version)
+		if fi, err := os.Stat(goDir); err == nil && fi.IsDir() {
+			gd.dirs = append(gd.dirs, goDir)
+			goDir = filepath.Join(goDir, machine)
+			if fi, err = os.Stat(goDir); err == nil && fi.IsDir() {
+				gd.dirs = append(gd.dirs, goDir)
+			}
+		}
+		if fi, err := os.Stat(dir); err == nil && fi.IsDir() {
+			lastDirs = append(lastDirs, dir)
+		}
+	}
+	gd.dirs = append(gd.dirs, lastDirs...)
+}
+
+// isStandard reports whether path is a standard library for gccgo.
+func (gd *gccgoDirs) isStandard(path string) bool {
+	// Quick check: if the first path component has a '.', it's not
+	// in the standard library. This skips most GOPATH directories.
+	i := strings.Index(path, "/")
+	if i < 0 {
+		i = len(path)
+	}
+	if strings.Contains(path[:i], ".") {
+		return false
+	}
+
+	if path == "unsafe" {
+		// Special case.
+		return true
+	}
+
+	gd.once.Do(gd.init)
+	if gd.dirs == nil {
+		// We couldn't find the gccgo search directories.
+		// Best guess, since the first component did not contain
+		// '.', is that this is a standard library package.
+		return true
+	}
+
+	for _, dir := range gd.dirs {
+		full := filepath.Join(dir, path) + ".gox"
+		if fi, err := os.Stat(full); err == nil && !fi.IsDir() {
+			return true
+		}
+	}
+
+	return false
+}
diff --git a/contrib/go/_std_1.20/src/internal/goroot/importcfg.go b/contrib/go/_std_1.20/src/internal/goroot/importcfg.go
new file mode 100644
index 0000000000..e324073746
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goroot/importcfg.go
@@ -0,0 +1,66 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package goroot
+
+import (
+	"bytes"
+	"fmt"
+	"os/exec"
+	"strings"
+	"sync"
+)
+
+// Importcfg returns an importcfg file to be passed to the
+// Go compiler that contains the cached paths for the .a files for the
+// standard library.
+func Importcfg() (string, error) {
+	var icfg bytes.Buffer
+
+	m, err := PkgfileMap()
+	if err != nil {
+		return "", err
+	}
+	fmt.Fprintf(&icfg, "# import config")
+	for importPath, export := range m {
+		fmt.Fprintf(&icfg, "\npackagefile %s=%s", importPath, export)
+	}
+	s := icfg.String()
+	return s, nil
+}
+
+var (
+	stdlibPkgfileMap map[string]string
+	stdlibPkgfileErr error
+	once             sync.Once
+)
+
+// PkgfileMap returns a map of package paths to the location on disk
+// of the .a file for the package.
+// The caller must not modify the map.
+func PkgfileMap() (map[string]string, error) {
+	once.Do(func() {
+		m := make(map[string]string)
+		output, err := exec.Command("go", "list", "-export", "-e", "-f", "{{.ImportPath}} {{.Export}}", "std", "cmd").Output()
+		if err != nil {
+			stdlibPkgfileErr = err
+		}
+		for _, line := range strings.Split(string(output), "\n") {
+			if line == "" {
+				continue
+			}
+			sp := strings.SplitN(line, " ", 2)
+			if len(sp) != 2 {
+				stdlibPkgfileErr = fmt.Errorf("determining pkgfile map: invalid line in go list output: %q", line)
+				return
+			}
+			importPath, export := sp[0], sp[1]
+			if export != "" {
+				m[importPath] = export
+			}
+		}
+		stdlibPkgfileMap = m
+	})
+	return stdlibPkgfileMap, stdlibPkgfileErr
+}
diff --git a/contrib/go/_std_1.20/src/internal/goroot/ya.make b/contrib/go/_std_1.20/src/internal/goroot/ya.make
new file mode 100644
index 0000000000..6dd7a3c141
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goroot/ya.make
@@ -0,0 +1,8 @@
+GO_LIBRARY()
+
+SRCS(
+    gc.go
+    importcfg.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/goversion/goversion.go b/contrib/go/_std_1.20/src/internal/goversion/goversion.go
new file mode 100644
index 0000000000..e9ecf8e643
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goversion/goversion.go
@@ -0,0 +1,12 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package goversion
+
+// Version is the Go 1.x version which is currently
+// in development and will eventually get released.
+//
+// It should be updated at the start of each development cycle to be
+// the version of the next Go 1.x release. See golang.org/issue/40705.
+const Version = 20
diff --git a/contrib/go/_std_1.20/src/internal/goversion/ya.make b/contrib/go/_std_1.20/src/internal/goversion/ya.make
new file mode 100644
index 0000000000..dee4610577
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/goversion/ya.make
@@ -0,0 +1,7 @@
+GO_LIBRARY()
+
+SRCS(
+    goversion.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/intern/intern.go b/contrib/go/_std_1.20/src/internal/intern/intern.go
new file mode 100644
index 0000000000..0e6852f729
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/intern/intern.go
@@ -0,0 +1,181 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package intern lets you make smaller comparable values by boxing
+// a larger comparable value (such as a 16 byte string header) down
+// into a globally unique 8 byte pointer.
+//
+// The globally unique pointers are garbage collected with weak
+// references and finalizers. This package hides that.
+package intern
+
+import (
+	"internal/godebug"
+	"runtime"
+	"sync"
+	"unsafe"
+)
+
+// A Value pointer is the handle to an underlying comparable value.
+// See func Get for how Value pointers may be used.
+type Value struct {
+	_      [0]func() // prevent people from accidentally using value type as comparable
+	cmpVal any
+	// resurrected is guarded by mu (for all instances of Value).
+	// It is set true whenever v is synthesized from a uintptr.
+	resurrected bool
+}
+
+// Get returns the comparable value passed to the Get func
+// that returned v.
+func (v *Value) Get() any { return v.cmpVal }
+
+// key is a key in our global value map.
+// It contains type-specialized fields to avoid allocations
+// when converting common types to empty interfaces.
+type key struct {
+	s      string
+	cmpVal any
+	// isString reports whether key contains a string.
+	// Without it, the zero value of key is ambiguous.
+	isString bool
+}
+
+// keyFor returns a key to use with cmpVal.
+func keyFor(cmpVal any) key {
+	if s, ok := cmpVal.(string); ok {
+		return key{s: s, isString: true}
+	}
+	return key{cmpVal: cmpVal}
+}
+
+// Value returns a *Value built from k.
+func (k key) Value() *Value {
+	if k.isString {
+		return &Value{cmpVal: k.s}
+	}
+	return &Value{cmpVal: k.cmpVal}
+}
+
+var (
+	// mu guards valMap, a weakref map of *Value by underlying value.
+	// It also guards the resurrected field of all *Values.
+	mu      sync.Mutex
+	valMap  = map[key]uintptr{} // to uintptr(*Value)
+	valSafe = safeMap()         // non-nil in safe+leaky mode
+)
+
+var intern = godebug.New("intern")
+
+// safeMap returns a non-nil map if we're in safe-but-leaky mode,
+// as controlled by GODEBUG=intern=leaky
+func safeMap() map[key]*Value {
+	if intern.Value() == "leaky" {
+		return map[key]*Value{}
+	}
+	return nil
+}
+
+// Get returns a pointer representing the comparable value cmpVal.
+//
+// The returned pointer will be the same for Get(v) and Get(v2)
+// if and only if v == v2, and can be used as a map key.
+func Get(cmpVal any) *Value {
+	return get(keyFor(cmpVal))
+}
+
+// GetByString is identical to Get, except that it is specialized for strings.
+// This avoids an allocation from putting a string into an interface{}
+// to pass as an argument to Get.
+func GetByString(s string) *Value {
+	return get(key{s: s, isString: true})
+}
+
+// We play unsafe games that violate Go's rules (and assume a non-moving
+// collector). So we quiet Go here.
+// See the comment below Get for more implementation details.
+//
+//go:nocheckptr
+func get(k key) *Value {
+	mu.Lock()
+	defer mu.Unlock()
+
+	var v *Value
+	if valSafe != nil {
+		v = valSafe[k]
+	} else if addr, ok := valMap[k]; ok {
+		v = (*Value)(unsafe.Pointer(addr))
+		v.resurrected = true
+	}
+	if v != nil {
+		return v
+	}
+	v = k.Value()
+	if valSafe != nil {
+		valSafe[k] = v
+	} else {
+		// SetFinalizer before uintptr conversion (theoretical concern;
+		// see https://github.com/go4org/intern/issues/13)
+		runtime.SetFinalizer(v, finalize)
+		valMap[k] = uintptr(unsafe.Pointer(v))
+	}
+	return v
+}
+
+func finalize(v *Value) {
+	mu.Lock()
+	defer mu.Unlock()
+	if v.resurrected {
+		// We lost the race. Somebody resurrected it while we
+		// were about to finalize it. Try again next round.
+		v.resurrected = false
+		runtime.SetFinalizer(v, finalize)
+		return
+	}
+	delete(valMap, keyFor(v.cmpVal))
+}
+
+// Interning is simple if you don't require that unused values be
+// garbage collectable. But we do require that; we don't want to be
+// DOS vector. We do this by using a uintptr to hide the pointer from
+// the garbage collector, and using a finalizer to eliminate the
+// pointer when no other code is using it.
+//
+// The obvious implementation of this is to use a
+// map[interface{}]uintptr-of-*interface{}, and set up a finalizer to
+// delete from the map. Unfortunately, this is racy. Because pointers
+// are being created in violation of Go's unsafety rules, it's
+// possible to create a pointer to a value concurrently with the GC
+// concluding that the value can be collected. There are other races
+// that break the equality invariant as well, but the use-after-free
+// will cause a runtime crash.
+//
+// To make this work, the finalizer needs to know that no references
+// have been unsafely created since the finalizer was set up. To do
+// this, values carry a "resurrected" sentinel, which gets set
+// whenever a pointer is unsafely created. If the finalizer encounters
+// the sentinel, it clears the sentinel and delays collection for one
+// additional GC cycle, by re-installing itself as finalizer. This
+// ensures that the unsafely created pointer is visible to the GC, and
+// will correctly prevent collection.
+//
+// This technique does mean that interned values that get reused take
+// at least 3 GC cycles to fully collect (1 to clear the sentinel, 1
+// to clean up the unsafe map, 1 to be actually deleted).
+//
+// @ianlancetaylor commented in
+// https://github.com/golang/go/issues/41303#issuecomment-717401656
+// that it is possible to implement weak references in terms of
+// finalizers without unsafe. Unfortunately, the approach he outlined
+// does not work here, for two reasons. First, there is no way to
+// construct a strong pointer out of a weak pointer; our map stores
+// weak pointers, but we must return strong pointers to callers.
+// Second, and more fundamentally, we must return not just _a_ strong
+// pointer to callers, but _the same_ strong pointer to callers. In
+// order to return _the same_ strong pointer to callers, we must track
+// it, which is exactly what we cannot do with strong pointers.
+//
+// See https://github.com/inetaf/netaddr/issues/53 for more
+// discussion, and https://github.com/go4org/intern/issues/2 for an
+// illustration of the subtleties at play.
diff --git a/contrib/go/_std_1.20/src/internal/intern/ya.make b/contrib/go/_std_1.20/src/internal/intern/ya.make
new file mode 100644
index 0000000000..25a446724a
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/intern/ya.make
@@ -0,0 +1,7 @@
+GO_LIBRARY()
+
+SRCS(
+    intern.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/itoa/itoa.go b/contrib/go/_std_1.20/src/internal/itoa/itoa.go
new file mode 100644
index 0000000000..c6062d9fe1
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/itoa/itoa.go
@@ -0,0 +1,33 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Simple conversions to avoid depending on strconv.
+
+package itoa
+
+// Itoa converts val to a decimal string.
+func Itoa(val int) string {
+	if val < 0 {
+		return "-" + Uitoa(uint(-val))
+	}
+	return Uitoa(uint(val))
+}
+
+// Uitoa converts val to a decimal string.
+func Uitoa(val uint) string {
+	if val == 0 { // avoid string allocation
+		return "0"
+	}
+	var buf [20]byte // big enough for 64bit value base 10
+	i := len(buf) - 1
+	for val >= 10 {
+		q := val / 10
+		buf[i] = byte('0' + val - q*10)
+		i--
+		val = q
+	}
+	// val < 10
+	buf[i] = byte('0' + val)
+	return string(buf[i:])
+}
diff --git a/contrib/go/_std_1.20/src/internal/itoa/ya.make b/contrib/go/_std_1.20/src/internal/itoa/ya.make
new file mode 100644
index 0000000000..f49dc1108e
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/itoa/ya.make
@@ -0,0 +1,7 @@
+GO_LIBRARY()
+
+SRCS(
+    itoa.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/lazyregexp/lazyre.go b/contrib/go/_std_1.20/src/internal/lazyregexp/lazyre.go
new file mode 100644
index 0000000000..2681af35af
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/lazyregexp/lazyre.go
@@ -0,0 +1,78 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package lazyregexp is a thin wrapper over regexp, allowing the use of global
+// regexp variables without forcing them to be compiled at init.
+package lazyregexp
+
+import (
+	"os"
+	"regexp"
+	"strings"
+	"sync"
+)
+
+// Regexp is a wrapper around regexp.Regexp, where the underlying regexp will be
+// compiled the first time it is needed.
+type Regexp struct {
+	str  string
+	once sync.Once
+	rx   *regexp.Regexp
+}
+
+func (r *Regexp) re() *regexp.Regexp {
+	r.once.Do(r.build)
+	return r.rx
+}
+
+func (r *Regexp) build() {
+	r.rx = regexp.MustCompile(r.str)
+	r.str = ""
+}
+
+func (r *Regexp) FindSubmatch(s []byte) [][]byte {
+	return r.re().FindSubmatch(s)
+}
+
+func (r *Regexp) FindStringSubmatch(s string) []string {
+	return r.re().FindStringSubmatch(s)
+}
+
+func (r *Regexp) FindStringSubmatchIndex(s string) []int {
+	return r.re().FindStringSubmatchIndex(s)
+}
+
+func (r *Regexp) ReplaceAllString(src, repl string) string {
+	return r.re().ReplaceAllString(src, repl)
+}
+
+func (r *Regexp) FindString(s string) string {
+	return r.re().FindString(s)
+}
+
+func (r *Regexp) FindAllString(s string, n int) []string {
+	return r.re().FindAllString(s, n)
+}
+
+func (r *Regexp) MatchString(s string) bool {
+	return r.re().MatchString(s)
+}
+
+func (r *Regexp) SubexpNames() []string {
+	return r.re().SubexpNames()
+}
+
+var inTest = len(os.Args) > 0 && strings.HasSuffix(strings.TrimSuffix(os.Args[0], ".exe"), ".test")
+
+// New creates a new lazy regexp, delaying the compiling work until it is first
+// needed. If the code is being run as part of tests, the regexp compiling will
+// happen immediately.
+func New(str string) *Regexp {
+	lr := &Regexp{str: str}
+	if inTest {
+		// In tests, always compile the regexps early.
+		lr.re()
+	}
+	return lr
+}
diff --git a/contrib/go/_std_1.20/src/internal/lazyregexp/ya.make b/contrib/go/_std_1.20/src/internal/lazyregexp/ya.make
new file mode 100644
index 0000000000..7753ef8e7d
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/lazyregexp/ya.make
@@ -0,0 +1,7 @@
+GO_LIBRARY()
+
+SRCS(
+    lazyre.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/nettrace/nettrace.go b/contrib/go/_std_1.20/src/internal/nettrace/nettrace.go
new file mode 100644
index 0000000000..0a2bf925e9
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/nettrace/nettrace.go
@@ -0,0 +1,46 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package nettrace contains internal hooks for tracing activity in
+// the net package. This package is purely internal for use by the
+// net/http/httptrace package and has no stable API exposed to end
+// users.
+package nettrace
+
+// TraceKey is a context.Context Value key. Its associated value should
+// be a *Trace struct.
+type TraceKey struct{}
+
+// LookupIPAltResolverKey is a context.Context Value key used by tests to
+// specify an alternate resolver func.
+// It is not exposed to outsider users. (But see issue 12503)
+// The value should be the same type as lookupIP:
+//
+//	func lookupIP(ctx context.Context, host string) ([]IPAddr, error)
+type LookupIPAltResolverKey struct{}
+
+// Trace contains a set of hooks for tracing events within
+// the net package. Any specific hook may be nil.
+type Trace struct {
+	// DNSStart is called with the hostname of a DNS lookup
+	// before it begins.
+	DNSStart func(name string)
+
+	// DNSDone is called after a DNS lookup completes (or fails).
+	// The coalesced parameter is whether singleflight de-duped
+	// the call. The addrs are of type net.IPAddr but can't
+	// actually be for circular dependency reasons.
+	DNSDone func(netIPs []any, coalesced bool, err error)
+
+	// ConnectStart is called before a Dial, excluding Dials made
+	// during DNS lookups. In the case of DualStack (Happy Eyeballs)
+	// dialing, this may be called multiple times, from multiple
+	// goroutines.
+	ConnectStart func(network, addr string)
+
+	// ConnectStart is called after a Dial with the results, excluding
+	// Dials made during DNS lookups. It may also be called multiple
+	// times, like ConnectStart.
+	ConnectDone func(network, addr string, err error)
+}
diff --git a/contrib/go/_std_1.20/src/internal/nettrace/ya.make b/contrib/go/_std_1.20/src/internal/nettrace/ya.make
new file mode 100644
index 0000000000..11bebb95db
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/nettrace/ya.make
@@ -0,0 +1,7 @@
+GO_LIBRARY()
+
+SRCS(
+    nettrace.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/oserror/errors.go b/contrib/go/_std_1.20/src/internal/oserror/errors.go
new file mode 100644
index 0000000000..28a1ab32d3
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/oserror/errors.go
@@ -0,0 +1,18 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package oserror defines errors values used in the os package.
+//
+// These types are defined here to permit the syscall package to reference them.
+package oserror
+
+import "errors"
+
+var (
+	ErrInvalid    = errors.New("invalid argument")
+	ErrPermission = errors.New("permission denied")
+	ErrExist      = errors.New("file already exists")
+	ErrNotExist   = errors.New("file does not exist")
+	ErrClosed     = errors.New("file already closed")
+)
diff --git a/contrib/go/_std_1.20/src/internal/oserror/ya.make b/contrib/go/_std_1.20/src/internal/oserror/ya.make
new file mode 100644
index 0000000000..22a9f40703
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/oserror/ya.make
@@ -0,0 +1,7 @@
+GO_LIBRARY()
+
+SRCS(
+    errors.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/pkgbits/codes.go b/contrib/go/_std_1.20/src/internal/pkgbits/codes.go
new file mode 100644
index 0000000000..f0cabde96e
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/pkgbits/codes.go
@@ -0,0 +1,77 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package pkgbits
+
+// A Code is an enum value that can be encoded into bitstreams.
+//
+// Code types are preferable for enum types, because they allow
+// Decoder to detect desyncs.
+type Code interface {
+	// Marker returns the SyncMarker for the Code's dynamic type.
+	Marker() SyncMarker
+
+	// Value returns the Code's ordinal value.
+	Value() int
+}
+
+// A CodeVal distinguishes among go/constant.Value encodings.
+type CodeVal int
+
+func (c CodeVal) Marker() SyncMarker { return SyncVal }
+func (c CodeVal) Value() int         { return int(c) }
+
+// Note: These values are public and cannot be changed without
+// updating the go/types importers.
+
+const (
+	ValBool CodeVal = iota
+	ValString
+	ValInt64
+	ValBigInt
+	ValBigRat
+	ValBigFloat
+)
+
+// A CodeType distinguishes among go/types.Type encodings.
+type CodeType int
+
+func (c CodeType) Marker() SyncMarker { return SyncType }
+func (c CodeType) Value() int         { return int(c) }
+
+// Note: These values are public and cannot be changed without
+// updating the go/types importers.
+
+const (
+	TypeBasic CodeType = iota
+	TypeNamed
+	TypePointer
+	TypeSlice
+	TypeArray
+	TypeChan
+	TypeMap
+	TypeSignature
+	TypeStruct
+	TypeInterface
+	TypeUnion
+	TypeTypeParam
+)
+
+// A CodeObj distinguishes among go/types.Object encodings.
+type CodeObj int
+
+func (c CodeObj) Marker() SyncMarker { return SyncCodeObj }
+func (c CodeObj) Value() int         { return int(c) }
+
+// Note: These values are public and cannot be changed without
+// updating the go/types importers.
+
+const (
+	ObjAlias CodeObj = iota
+	ObjConst
+	ObjType
+	ObjFunc
+	ObjVar
+	ObjStub
+)
diff --git a/contrib/go/_std_1.20/src/internal/pkgbits/decoder.go b/contrib/go/_std_1.20/src/internal/pkgbits/decoder.go
new file mode 100644
index 0000000000..4fe024d4f1
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/pkgbits/decoder.go
@@ -0,0 +1,515 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package pkgbits
+
+import (
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"go/constant"
+	"go/token"
+	"io"
+	"math/big"
+	"os"
+	"runtime"
+	"strings"
+)
+
+// A PkgDecoder provides methods for decoding a package's Unified IR
+// export data.
+type PkgDecoder struct {
+	// version is the file format version.
+	version uint32
+
+	// sync indicates whether the file uses sync markers.
+	sync bool
+
+	// pkgPath is the package path for the package to be decoded.
+	//
+	// TODO(mdempsky): Remove; unneeded since CL 391014.
+	pkgPath string
+
+	// elemData is the full data payload of the encoded package.
+	// Elements are densely and contiguously packed together.
+	//
+	// The last 8 bytes of elemData are the package fingerprint.
+	elemData string
+
+	// elemEnds stores the byte-offset end positions of element
+	// bitstreams within elemData.
+	//
+	// For example, element I's bitstream data starts at elemEnds[I-1]
+	// (or 0, if I==0) and ends at elemEnds[I].
+	//
+	// Note: elemEnds is indexed by absolute indices, not
+	// section-relative indices.
+	elemEnds []uint32
+
+	// elemEndsEnds stores the index-offset end positions of relocation
+	// sections within elemEnds.
+	//
+	// For example, section K's end positions start at elemEndsEnds[K-1]
+	// (or 0, if K==0) and end at elemEndsEnds[K].
+	elemEndsEnds [numRelocs]uint32
+
+	scratchRelocEnt []RelocEnt
+}
+
+// PkgPath returns the package path for the package
+//
+// TODO(mdempsky): Remove; unneeded since CL 391014.
+func (pr *PkgDecoder) PkgPath() string { return pr.pkgPath }
+
+// SyncMarkers reports whether pr uses sync markers.
+func (pr *PkgDecoder) SyncMarkers() bool { return pr.sync }
+
+// NewPkgDecoder returns a PkgDecoder initialized to read the Unified
+// IR export data from input. pkgPath is the package path for the
+// compilation unit that produced the export data.
+//
+// TODO(mdempsky): Remove pkgPath parameter; unneeded since CL 391014.
+func NewPkgDecoder(pkgPath, input string) PkgDecoder {
+	pr := PkgDecoder{
+		pkgPath: pkgPath,
+	}
+
+	// TODO(mdempsky): Implement direct indexing of input string to
+	// avoid copying the position information.
+
+	r := strings.NewReader(input)
+
+	assert(binary.Read(r, binary.LittleEndian, &pr.version) == nil)
+
+	switch pr.version {
+	default:
+		panic(fmt.Errorf("unsupported version: %v", pr.version))
+	case 0:
+		// no flags
+	case 1:
+		var flags uint32
+		assert(binary.Read(r, binary.LittleEndian, &flags) == nil)
+		pr.sync = flags&flagSyncMarkers != 0
+	}
+
+	assert(binary.Read(r, binary.LittleEndian, pr.elemEndsEnds[:]) == nil)
+
+	pr.elemEnds = make([]uint32, pr.elemEndsEnds[len(pr.elemEndsEnds)-1])
+	assert(binary.Read(r, binary.LittleEndian, pr.elemEnds[:]) == nil)
+
+	pos, err := r.Seek(0, io.SeekCurrent)
+	assert(err == nil)
+
+	pr.elemData = input[pos:]
+	assert(len(pr.elemData)-8 == int(pr.elemEnds[len(pr.elemEnds)-1]))
+
+	return pr
+}
+
+// NumElems returns the number of elements in section k.
+func (pr *PkgDecoder) NumElems(k RelocKind) int {
+	count := int(pr.elemEndsEnds[k])
+	if k > 0 {
+		count -= int(pr.elemEndsEnds[k-1])
+	}
+	return count
+}
+
+// TotalElems returns the total number of elements across all sections.
+func (pr *PkgDecoder) TotalElems() int {
+	return len(pr.elemEnds)
+}
+
+// Fingerprint returns the package fingerprint.
+func (pr *PkgDecoder) Fingerprint() [8]byte {
+	var fp [8]byte
+	copy(fp[:], pr.elemData[len(pr.elemData)-8:])
+	return fp
+}
+
+// AbsIdx returns the absolute index for the given (section, index)
+// pair.
+func (pr *PkgDecoder) AbsIdx(k RelocKind, idx Index) int {
+	absIdx := int(idx)
+	if k > 0 {
+		absIdx += int(pr.elemEndsEnds[k-1])
+	}
+	if absIdx >= int(pr.elemEndsEnds[k]) {
+		errorf("%v:%v is out of bounds; %v", k, idx, pr.elemEndsEnds)
+	}
+	return absIdx
+}
+
+// DataIdx returns the raw element bitstream for the given (section,
+// index) pair.
+func (pr *PkgDecoder) DataIdx(k RelocKind, idx Index) string {
+	absIdx := pr.AbsIdx(k, idx)
+
+	var start uint32
+	if absIdx > 0 {
+		start = pr.elemEnds[absIdx-1]
+	}
+	end := pr.elemEnds[absIdx]
+
+	return pr.elemData[start:end]
+}
+
+// StringIdx returns the string value for the given string index.
+func (pr *PkgDecoder) StringIdx(idx Index) string {
+	return pr.DataIdx(RelocString, idx)
+}
+
+// NewDecoder returns a Decoder for the given (section, index) pair,
+// and decodes the given SyncMarker from the element bitstream.
+func (pr *PkgDecoder) NewDecoder(k RelocKind, idx Index, marker SyncMarker) Decoder {
+	r := pr.NewDecoderRaw(k, idx)
+	r.Sync(marker)
+	return r
+}
+
+// TempDecoder returns a Decoder for the given (section, index) pair,
+// and decodes the given SyncMarker from the element bitstream.
+// If possible the Decoder should be RetireDecoder'd when it is no longer
+// needed, this will avoid heap allocations.
+func (pr *PkgDecoder) TempDecoder(k RelocKind, idx Index, marker SyncMarker) Decoder {
+	r := pr.TempDecoderRaw(k, idx)
+	r.Sync(marker)
+	return r
+}
+
+func (pr *PkgDecoder) RetireDecoder(d *Decoder) {
+	pr.scratchRelocEnt = d.Relocs
+	d.Relocs = nil
+}
+
+// NewDecoderRaw returns a Decoder for the given (section, index) pair.
+//
+// Most callers should use NewDecoder instead.
+func (pr *PkgDecoder) NewDecoderRaw(k RelocKind, idx Index) Decoder {
+	r := Decoder{
+		common: pr,
+		k:      k,
+		Idx:    idx,
+	}
+
+	r.Data.Reset(pr.DataIdx(k, idx))
+	r.Sync(SyncRelocs)
+	r.Relocs = make([]RelocEnt, r.Len())
+	for i := range r.Relocs {
+		r.Sync(SyncReloc)
+		r.Relocs[i] = RelocEnt{RelocKind(r.Len()), Index(r.Len())}
+	}
+
+	return r
+}
+
+func (pr *PkgDecoder) TempDecoderRaw(k RelocKind, idx Index) Decoder {
+	r := Decoder{
+		common: pr,
+		k:      k,
+		Idx:    idx,
+	}
+
+	r.Data.Reset(pr.DataIdx(k, idx))
+	r.Sync(SyncRelocs)
+	l := r.Len()
+	if cap(pr.scratchRelocEnt) >= l {
+		r.Relocs = pr.scratchRelocEnt[:l]
+		pr.scratchRelocEnt = nil
+	} else {
+		r.Relocs = make([]RelocEnt, l)
+	}
+	for i := range r.Relocs {
+		r.Sync(SyncReloc)
+		r.Relocs[i] = RelocEnt{RelocKind(r.Len()), Index(r.Len())}
+	}
+
+	return r
+}
+
+// A Decoder provides methods for decoding an individual element's
+// bitstream data.
+type Decoder struct {
+	common *PkgDecoder
+
+	Relocs []RelocEnt
+	Data   strings.Reader
+
+	k   RelocKind
+	Idx Index
+}
+
+func (r *Decoder) checkErr(err error) {
+	if err != nil {
+		errorf("unexpected decoding error: %w", err)
+	}
+}
+
+func (r *Decoder) rawUvarint() uint64 {
+	x, err := readUvarint(&r.Data)
+	r.checkErr(err)
+	return x
+}
+
+// readUvarint is a type-specialized copy of encoding/binary.ReadUvarint.
+// This avoids the interface conversion and thus has better escape properties,
+// which flows up the stack.
+func readUvarint(r *strings.Reader) (uint64, error) {
+	var x uint64
+	var s uint
+	for i := 0; i < binary.MaxVarintLen64; i++ {
+		b, err := r.ReadByte()
+		if err != nil {
+			if i > 0 && err == io.EOF {
+				err = io.ErrUnexpectedEOF
+			}
+			return x, err
+		}
+		if b < 0x80 {
+			if i == binary.MaxVarintLen64-1 && b > 1 {
+				return x, overflow
+			}
+			return x | uint64(b)<<s, nil
+		}
+		x |= uint64(b&0x7f) << s
+		s += 7
+	}
+	return x, overflow
+}
+
+var overflow = errors.New("pkgbits: readUvarint overflows a 64-bit integer")
+
+func (r *Decoder) rawVarint() int64 {
+	ux := r.rawUvarint()
+
+	// Zig-zag decode.
+	x := int64(ux >> 1)
+	if ux&1 != 0 {
+		x = ^x
+	}
+	return x
+}
+
+func (r *Decoder) rawReloc(k RelocKind, idx int) Index {
+	e := r.Relocs[idx]
+	assert(e.Kind == k)
+	return e.Idx
+}
+
+// Sync decodes a sync marker from the element bitstream and asserts
+// that it matches the expected marker.
+//
+// If EnableSync is false, then Sync is a no-op.
+func (r *Decoder) Sync(mWant SyncMarker) {
+	if !r.common.sync {
+		return
+	}
+
+	pos, _ := r.Data.Seek(0, io.SeekCurrent)
+	mHave := SyncMarker(r.rawUvarint())
+	writerPCs := make([]int, r.rawUvarint())
+	for i := range writerPCs {
+		writerPCs[i] = int(r.rawUvarint())
+	}
+
+	if mHave == mWant {
+		return
+	}
+
+	// There's some tension here between printing:
+	//
+	// (1) full file paths that tools can recognize (e.g., so emacs
+	//     hyperlinks the "file:line" text for easy navigation), or
+	//
+	// (2) short file paths that are easier for humans to read (e.g., by
+	//     omitting redundant or irrelevant details, so it's easier to
+	//     focus on the useful bits that remain).
+	//
+	// The current formatting favors the former, as it seems more
+	// helpful in practice. But perhaps the formatting could be improved
+	// to better address both concerns. For example, use relative file
+	// paths if they would be shorter, or rewrite file paths to contain
+	// "$GOROOT" (like objabi.AbsFile does) if tools can be taught how
+	// to reliably expand that again.
+
+	fmt.Printf("export data desync: package %q, section %v, index %v, offset %v\n", r.common.pkgPath, r.k, r.Idx, pos)
+
+	fmt.Printf("\nfound %v, written at:\n", mHave)
+	if len(writerPCs) == 0 {
+		fmt.Printf("\t[stack trace unavailable; recompile package %q with -d=syncframes]\n", r.common.pkgPath)
+	}
+	for _, pc := range writerPCs {
+		fmt.Printf("\t%s\n", r.common.StringIdx(r.rawReloc(RelocString, pc)))
+	}
+
+	fmt.Printf("\nexpected %v, reading at:\n", mWant)
+	var readerPCs [32]uintptr // TODO(mdempsky): Dynamically size?
+	n := runtime.Callers(2, readerPCs[:])
+	for _, pc := range fmtFrames(readerPCs[:n]...) {
+		fmt.Printf("\t%s\n", pc)
+	}
+
+	// We already printed a stack trace for the reader, so now we can
+	// simply exit. Printing a second one with panic or base.Fatalf
+	// would just be noise.
+	os.Exit(1)
+}
+
+// Bool decodes and returns a bool value from the element bitstream.
+func (r *Decoder) Bool() bool {
+	r.Sync(SyncBool)
+	x, err := r.Data.ReadByte()
+	r.checkErr(err)
+	assert(x < 2)
+	return x != 0
+}
+
+// Int64 decodes and returns an int64 value from the element bitstream.
+func (r *Decoder) Int64() int64 {
+	r.Sync(SyncInt64)
+	return r.rawVarint()
+}
+
+// Int64 decodes and returns a uint64 value from the element bitstream.
+func (r *Decoder) Uint64() uint64 {
+	r.Sync(SyncUint64)
+	return r.rawUvarint()
+}
+
+// Len decodes and returns a non-negative int value from the element bitstream.
+func (r *Decoder) Len() int { x := r.Uint64(); v := int(x); assert(uint64(v) == x); return v }
+
+// Int decodes and returns an int value from the element bitstream.
+func (r *Decoder) Int() int { x := r.Int64(); v := int(x); assert(int64(v) == x); return v }
+
+// Uint decodes and returns a uint value from the element bitstream.
+func (r *Decoder) Uint() uint { x := r.Uint64(); v := uint(x); assert(uint64(v) == x); return v }
+
+// Code decodes a Code value from the element bitstream and returns
+// its ordinal value. It's the caller's responsibility to convert the
+// result to an appropriate Code type.
+//
+// TODO(mdempsky): Ideally this method would have signature "Code[T
+// Code] T" instead, but we don't allow generic methods and the
+// compiler can't depend on generics yet anyway.
+func (r *Decoder) Code(mark SyncMarker) int {
+	r.Sync(mark)
+	return r.Len()
+}
+
+// Reloc decodes a relocation of expected section k from the element
+// bitstream and returns an index to the referenced element.
+func (r *Decoder) Reloc(k RelocKind) Index {
+	r.Sync(SyncUseReloc)
+	return r.rawReloc(k, r.Len())
+}
+
+// String decodes and returns a string value from the element
+// bitstream.
+func (r *Decoder) String() string {
+	r.Sync(SyncString)
+	return r.common.StringIdx(r.Reloc(RelocString))
+}
+
+// Strings decodes and returns a variable-length slice of strings from
+// the element bitstream.
+func (r *Decoder) Strings() []string {
+	res := make([]string, r.Len())
+	for i := range res {
+		res[i] = r.String()
+	}
+	return res
+}
+
+// Value decodes and returns a constant.Value from the element
+// bitstream.
+func (r *Decoder) Value() constant.Value {
+	r.Sync(SyncValue)
+	isComplex := r.Bool()
+	val := r.scalar()
+	if isComplex {
+		val = constant.BinaryOp(val, token.ADD, constant.MakeImag(r.scalar()))
+	}
+	return val
+}
+
+func (r *Decoder) scalar() constant.Value {
+	switch tag := CodeVal(r.Code(SyncVal)); tag {
+	default:
+		panic(fmt.Errorf("unexpected scalar tag: %v", tag))
+
+	case ValBool:
+		return constant.MakeBool(r.Bool())
+	case ValString:
+		return constant.MakeString(r.String())
+	case ValInt64:
+		return constant.MakeInt64(r.Int64())
+	case ValBigInt:
+		return constant.Make(r.bigInt())
+	case ValBigRat:
+		num := r.bigInt()
+		denom := r.bigInt()
+		return constant.Make(new(big.Rat).SetFrac(num, denom))
+	case ValBigFloat:
+		return constant.Make(r.bigFloat())
+	}
+}
+
+func (r *Decoder) bigInt() *big.Int {
+	v := new(big.Int).SetBytes([]byte(r.String()))
+	if r.Bool() {
+		v.Neg(v)
+	}
+	return v
+}
+
+func (r *Decoder) bigFloat() *big.Float {
+	v := new(big.Float).SetPrec(512)
+	assert(v.UnmarshalText([]byte(r.String())) == nil)
+	return v
+}
+
+// @@@ Helpers
+
+// TODO(mdempsky): These should probably be removed. I think they're a
+// smell that the export data format is not yet quite right.
+
+// PeekPkgPath returns the package path for the specified package
+// index.
+func (pr *PkgDecoder) PeekPkgPath(idx Index) string {
+	var path string
+	{
+		r := pr.TempDecoder(RelocPkg, idx, SyncPkgDef)
+		path = r.String()
+		pr.RetireDecoder(&r)
+	}
+	if path == "" {
+		path = pr.pkgPath
+	}
+	return path
+}
+
+// PeekObj returns the package path, object name, and CodeObj for the
+// specified object index.
+func (pr *PkgDecoder) PeekObj(idx Index) (string, string, CodeObj) {
+	var ridx Index
+	var name string
+	var rcode int
+	{
+		r := pr.TempDecoder(RelocName, idx, SyncObject1)
+		r.Sync(SyncSym)
+		r.Sync(SyncPkg)
+		ridx = r.Reloc(RelocPkg)
+		name = r.String()
+		rcode = r.Code(SyncCodeObj)
+		pr.RetireDecoder(&r)
+	}
+
+	path := pr.PeekPkgPath(ridx)
+	assert(name != "")
+
+	tag := CodeObj(rcode)
+
+	return path, name, tag
+}
diff --git a/contrib/go/_std_1.20/src/internal/pkgbits/doc.go b/contrib/go/_std_1.20/src/internal/pkgbits/doc.go
new file mode 100644
index 0000000000..4862e39049
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/pkgbits/doc.go
@@ -0,0 +1,30 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package pkgbits implements low-level coding abstractions for
+// Unified IR's export data format.
+//
+// At a low-level, a package is a collection of bitstream elements.
+// Each element has a "kind" and a dense, non-negative index.
+// Elements can be randomly accessed given their kind and index.
+//
+// Individual elements are sequences of variable-length values (e.g.,
+// integers, booleans, strings, go/constant values, cross-references
+// to other elements). Package pkgbits provides APIs for encoding and
+// decoding these low-level values, but the details of mapping
+// higher-level Go constructs into elements is left to higher-level
+// abstractions.
+//
+// Elements may cross-reference each other with "relocations." For
+// example, an element representing a pointer type has a relocation
+// referring to the element type.
+//
+// Go constructs may be composed as a constellation of multiple
+// elements. For example, a declared function may have one element to
+// describe the object (e.g., its name, type, position), and a
+// separate element to describe its function body. This allows readers
+// some flexibility in efficiently seeking or re-reading data (e.g.,
+// inlining requires re-reading the function body for each inlined
+// call, without needing to re-read the object-level details).
+package pkgbits
diff --git a/contrib/go/_std_1.20/src/internal/pkgbits/encoder.go b/contrib/go/_std_1.20/src/internal/pkgbits/encoder.go
new file mode 100644
index 0000000000..70a2cbae51
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/pkgbits/encoder.go
@@ -0,0 +1,394 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package pkgbits
+
+import (
+	"bytes"
+	"crypto/md5"
+	"encoding/binary"
+	"go/constant"
+	"io"
+	"math/big"
+	"runtime"
+	"strings"
+)
+
+// currentVersion is the current version number.
+//
+//   - v0: initial prototype
+//
+//   - v1: adds the flags uint32 word
+//
+// TODO(mdempsky): For the next version bump:
+//   - remove the legacy "has init" bool from the public root
+//   - remove obj's "derived func instance" bool
+const currentVersion uint32 = 1
+
+// A PkgEncoder provides methods for encoding a package's Unified IR
+// export data.
+type PkgEncoder struct {
+	// elems holds the bitstream for previously encoded elements.
+	elems [numRelocs][]string
+
+	// stringsIdx maps previously encoded strings to their index within
+	// the RelocString section, to allow deduplication. That is,
+	// elems[RelocString][stringsIdx[s]] == s (if present).
+	stringsIdx map[string]Index
+
+	// syncFrames is the number of frames to write at each sync
+	// marker. A negative value means sync markers are omitted.
+	syncFrames int
+}
+
+// SyncMarkers reports whether pw uses sync markers.
+func (pw *PkgEncoder) SyncMarkers() bool { return pw.syncFrames >= 0 }
+
+// NewPkgEncoder returns an initialized PkgEncoder.
+//
+// syncFrames is the number of caller frames that should be serialized
+// at Sync points. Serializing additional frames results in larger
+// export data files, but can help diagnosing desync errors in
+// higher-level Unified IR reader/writer code. If syncFrames is
+// negative, then sync markers are omitted entirely.
+func NewPkgEncoder(syncFrames int) PkgEncoder {
+	return PkgEncoder{
+		stringsIdx: make(map[string]Index),
+		syncFrames: syncFrames,
+	}
+}
+
+// DumpTo writes the package's encoded data to out0 and returns the
+// package fingerprint.
+func (pw *PkgEncoder) DumpTo(out0 io.Writer) (fingerprint [8]byte) {
+	h := md5.New()
+	out := io.MultiWriter(out0, h)
+
+	writeUint32 := func(x uint32) {
+		assert(binary.Write(out, binary.LittleEndian, x) == nil)
+	}
+
+	writeUint32(currentVersion)
+
+	var flags uint32
+	if pw.SyncMarkers() {
+		flags |= flagSyncMarkers
+	}
+	writeUint32(flags)
+
+	// Write elemEndsEnds.
+	var sum uint32
+	for _, elems := range &pw.elems {
+		sum += uint32(len(elems))
+		writeUint32(sum)
+	}
+
+	// Write elemEnds.
+	sum = 0
+	for _, elems := range &pw.elems {
+		for _, elem := range elems {
+			sum += uint32(len(elem))
+			writeUint32(sum)
+		}
+	}
+
+	// Write elemData.
+	for _, elems := range &pw.elems {
+		for _, elem := range elems {
+			_, err := io.WriteString(out, elem)
+			assert(err == nil)
+		}
+	}
+
+	// Write fingerprint.
+	copy(fingerprint[:], h.Sum(nil))
+	_, err := out0.Write(fingerprint[:])
+	assert(err == nil)
+
+	return
+}
+
+// StringIdx adds a string value to the strings section, if not
+// already present, and returns its index.
+func (pw *PkgEncoder) StringIdx(s string) Index {
+	if idx, ok := pw.stringsIdx[s]; ok {
+		assert(pw.elems[RelocString][idx] == s)
+		return idx
+	}
+
+	idx := Index(len(pw.elems[RelocString]))
+	pw.elems[RelocString] = append(pw.elems[RelocString], s)
+	pw.stringsIdx[s] = idx
+	return idx
+}
+
+// NewEncoder returns an Encoder for a new element within the given
+// section, and encodes the given SyncMarker as the start of the
+// element bitstream.
+func (pw *PkgEncoder) NewEncoder(k RelocKind, marker SyncMarker) Encoder {
+	e := pw.NewEncoderRaw(k)
+	e.Sync(marker)
+	return e
+}
+
+// NewEncoderRaw returns an Encoder for a new element within the given
+// section.
+//
+// Most callers should use NewEncoder instead.
+func (pw *PkgEncoder) NewEncoderRaw(k RelocKind) Encoder {
+	idx := Index(len(pw.elems[k]))
+	pw.elems[k] = append(pw.elems[k], "") // placeholder
+
+	return Encoder{
+		p:   pw,
+		k:   k,
+		Idx: idx,
+	}
+}
+
+// An Encoder provides methods for encoding an individual element's
+// bitstream data.
+type Encoder struct {
+	p *PkgEncoder
+
+	Relocs   []RelocEnt
+	RelocMap map[RelocEnt]uint32
+	Data     bytes.Buffer // accumulated element bitstream data
+
+	encodingRelocHeader bool
+
+	k   RelocKind
+	Idx Index // index within relocation section
+}
+
+// Flush finalizes the element's bitstream and returns its Index.
+func (w *Encoder) Flush() Index {
+	var sb strings.Builder
+
+	// Backup the data so we write the relocations at the front.
+	var tmp bytes.Buffer
+	io.Copy(&tmp, &w.Data)
+
+	// TODO(mdempsky): Consider writing these out separately so they're
+	// easier to strip, along with function bodies, so that we can prune
+	// down to just the data that's relevant to go/types.
+	if w.encodingRelocHeader {
+		panic("encodingRelocHeader already true; recursive flush?")
+	}
+	w.encodingRelocHeader = true
+	w.Sync(SyncRelocs)
+	w.Len(len(w.Relocs))
+	for _, rEnt := range w.Relocs {
+		w.Sync(SyncReloc)
+		w.Len(int(rEnt.Kind))
+		w.Len(int(rEnt.Idx))
+	}
+
+	io.Copy(&sb, &w.Data)
+	io.Copy(&sb, &tmp)
+	w.p.elems[w.k][w.Idx] = sb.String()
+
+	return w.Idx
+}
+
+func (w *Encoder) checkErr(err error) {
+	if err != nil {
+		errorf("unexpected encoding error: %v", err)
+	}
+}
+
+func (w *Encoder) rawUvarint(x uint64) {
+	var buf [binary.MaxVarintLen64]byte
+	n := binary.PutUvarint(buf[:], x)
+	_, err := w.Data.Write(buf[:n])
+	w.checkErr(err)
+}
+
+func (w *Encoder) rawVarint(x int64) {
+	// Zig-zag encode.
+	ux := uint64(x) << 1
+	if x < 0 {
+		ux = ^ux
+	}
+
+	w.rawUvarint(ux)
+}
+
+func (w *Encoder) rawReloc(r RelocKind, idx Index) int {
+	e := RelocEnt{r, idx}
+	if w.RelocMap != nil {
+		if i, ok := w.RelocMap[e]; ok {
+			return int(i)
+		}
+	} else {
+		w.RelocMap = make(map[RelocEnt]uint32)
+	}
+
+	i := len(w.Relocs)
+	w.RelocMap[e] = uint32(i)
+	w.Relocs = append(w.Relocs, e)
+	return i
+}
+
+func (w *Encoder) Sync(m SyncMarker) {
+	if !w.p.SyncMarkers() {
+		return
+	}
+
+	// Writing out stack frame string references requires working
+	// relocations, but writing out the relocations themselves involves
+	// sync markers. To prevent infinite recursion, we simply trim the
+	// stack frame for sync markers within the relocation header.
+	var frames []string
+	if !w.encodingRelocHeader && w.p.syncFrames > 0 {
+		pcs := make([]uintptr, w.p.syncFrames)
+		n := runtime.Callers(2, pcs)
+		frames = fmtFrames(pcs[:n]...)
+	}
+
+	// TODO(mdempsky): Save space by writing out stack frames as a
+	// linked list so we can share common stack frames.
+	w.rawUvarint(uint64(m))
+	w.rawUvarint(uint64(len(frames)))
+	for _, frame := range frames {
+		w.rawUvarint(uint64(w.rawReloc(RelocString, w.p.StringIdx(frame))))
+	}
+}
+
+// Bool encodes and writes a bool value into the element bitstream,
+// and then returns the bool value.
+//
+// For simple, 2-alternative encodings, the idiomatic way to call Bool
+// is something like:
+//
+//	if w.Bool(x != 0) {
+//		// alternative #1
+//	} else {
+//		// alternative #2
+//	}
+//
+// For multi-alternative encodings, use Code instead.
+func (w *Encoder) Bool(b bool) bool {
+	w.Sync(SyncBool)
+	var x byte
+	if b {
+		x = 1
+	}
+	err := w.Data.WriteByte(x)
+	w.checkErr(err)
+	return b
+}
+
+// Int64 encodes and writes an int64 value into the element bitstream.
+func (w *Encoder) Int64(x int64) {
+	w.Sync(SyncInt64)
+	w.rawVarint(x)
+}
+
+// Uint64 encodes and writes a uint64 value into the element bitstream.
+func (w *Encoder) Uint64(x uint64) {
+	w.Sync(SyncUint64)
+	w.rawUvarint(x)
+}
+
+// Len encodes and writes a non-negative int value into the element bitstream.
+func (w *Encoder) Len(x int) { assert(x >= 0); w.Uint64(uint64(x)) }
+
+// Int encodes and writes an int value into the element bitstream.
+func (w *Encoder) Int(x int) { w.Int64(int64(x)) }
+
+// Len encodes and writes a uint value into the element bitstream.
+func (w *Encoder) Uint(x uint) { w.Uint64(uint64(x)) }
+
+// Reloc encodes and writes a relocation for the given (section,
+// index) pair into the element bitstream.
+//
+// Note: Only the index is formally written into the element
+// bitstream, so bitstream decoders must know from context which
+// section an encoded relocation refers to.
+func (w *Encoder) Reloc(r RelocKind, idx Index) {
+	w.Sync(SyncUseReloc)
+	w.Len(w.rawReloc(r, idx))
+}
+
+// Code encodes and writes a Code value into the element bitstream.
+func (w *Encoder) Code(c Code) {
+	w.Sync(c.Marker())
+	w.Len(c.Value())
+}
+
+// String encodes and writes a string value into the element
+// bitstream.
+//
+// Internally, strings are deduplicated by adding them to the strings
+// section (if not already present), and then writing a relocation
+// into the element bitstream.
+func (w *Encoder) String(s string) {
+	w.StringRef(w.p.StringIdx(s))
+}
+
+// StringRef writes a reference to the given index, which must be a
+// previously encoded string value.
+func (w *Encoder) StringRef(idx Index) {
+	w.Sync(SyncString)
+	w.Reloc(RelocString, idx)
+}
+
+// Strings encodes and writes a variable-length slice of strings into
+// the element bitstream.
+func (w *Encoder) Strings(ss []string) {
+	w.Len(len(ss))
+	for _, s := range ss {
+		w.String(s)
+	}
+}
+
+// Value encodes and writes a constant.Value into the element
+// bitstream.
+func (w *Encoder) Value(val constant.Value) {
+	w.Sync(SyncValue)
+	if w.Bool(val.Kind() == constant.Complex) {
+		w.scalar(constant.Real(val))
+		w.scalar(constant.Imag(val))
+	} else {
+		w.scalar(val)
+	}
+}
+
+func (w *Encoder) scalar(val constant.Value) {
+	switch v := constant.Val(val).(type) {
+	default:
+		errorf("unhandled %v (%v)", val, val.Kind())
+	case bool:
+		w.Code(ValBool)
+		w.Bool(v)
+	case string:
+		w.Code(ValString)
+		w.String(v)
+	case int64:
+		w.Code(ValInt64)
+		w.Int64(v)
+	case *big.Int:
+		w.Code(ValBigInt)
+		w.bigInt(v)
+	case *big.Rat:
+		w.Code(ValBigRat)
+		w.bigInt(v.Num())
+		w.bigInt(v.Denom())
+	case *big.Float:
+		w.Code(ValBigFloat)
+		w.bigFloat(v)
+	}
+}
+
+func (w *Encoder) bigInt(v *big.Int) {
+	b := v.Bytes()
+	w.String(string(b)) // TODO: More efficient encoding.
+	w.Bool(v.Sign() < 0)
+}
+
+func (w *Encoder) bigFloat(v *big.Float) {
+	b := v.Append(nil, 'p', -1)
+	w.String(string(b)) // TODO: More efficient encoding.
+}
diff --git a/contrib/go/_std_1.20/src/internal/pkgbits/flags.go b/contrib/go/_std_1.20/src/internal/pkgbits/flags.go
new file mode 100644
index 0000000000..654222745f
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/pkgbits/flags.go
@@ -0,0 +1,9 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package pkgbits
+
+const (
+	flagSyncMarkers = 1 << iota // file format contains sync markers
+)
diff --git a/contrib/go/_std_1.20/src/internal/pkgbits/reloc.go b/contrib/go/_std_1.20/src/internal/pkgbits/reloc.go
new file mode 100644
index 0000000000..fcdfb97ca9
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/pkgbits/reloc.go
@@ -0,0 +1,42 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package pkgbits
+
+// A RelocKind indicates a particular section within a unified IR export.
+type RelocKind int32
+
+// An Index represents a bitstream element index within a particular
+// section.
+type Index int32
+
+// A relocEnt (relocation entry) is an entry in an element's local
+// reference table.
+//
+// TODO(mdempsky): Rename this too.
+type RelocEnt struct {
+	Kind RelocKind
+	Idx  Index
+}
+
+// Reserved indices within the meta relocation section.
+const (
+	PublicRootIdx  Index = 0
+	PrivateRootIdx Index = 1
+)
+
+const (
+	RelocString RelocKind = iota
+	RelocMeta
+	RelocPosBase
+	RelocPkg
+	RelocName
+	RelocType
+	RelocObj
+	RelocObjExt
+	RelocObjDict
+	RelocBody
+
+	numRelocs = iota
+)
diff --git a/contrib/go/_std_1.20/src/internal/pkgbits/support.go b/contrib/go/_std_1.20/src/internal/pkgbits/support.go
new file mode 100644
index 0000000000..f7579dfdc4
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/pkgbits/support.go
@@ -0,0 +1,17 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package pkgbits
+
+import "fmt"
+
+func assert(b bool) {
+	if !b {
+		panic("assertion failed")
+	}
+}
+
+func errorf(format string, args ...any) {
+	panic(fmt.Errorf(format, args...))
+}
diff --git a/contrib/go/_std_1.20/src/internal/pkgbits/sync.go b/contrib/go/_std_1.20/src/internal/pkgbits/sync.go
new file mode 100644
index 0000000000..1520b73afb
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/pkgbits/sync.go
@@ -0,0 +1,136 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package pkgbits
+
+import (
+	"fmt"
+	"runtime"
+	"strings"
+)
+
+// fmtFrames formats a backtrace for reporting reader/writer desyncs.
+func fmtFrames(pcs ...uintptr) []string {
+	res := make([]string, 0, len(pcs))
+	walkFrames(pcs, func(file string, line int, name string, offset uintptr) {
+		// Trim package from function name. It's just redundant noise.
+		name = strings.TrimPrefix(name, "cmd/compile/internal/noder.")
+
+		res = append(res, fmt.Sprintf("%s:%v: %s +0x%v", file, line, name, offset))
+	})
+	return res
+}
+
+type frameVisitor func(file string, line int, name string, offset uintptr)
+
+// walkFrames calls visit for each call frame represented by pcs.
+//
+// pcs should be a slice of PCs, as returned by runtime.Callers.
+func walkFrames(pcs []uintptr, visit frameVisitor) {
+	if len(pcs) == 0 {
+		return
+	}
+
+	frames := runtime.CallersFrames(pcs)
+	for {
+		frame, more := frames.Next()
+		visit(frame.File, frame.Line, frame.Function, frame.PC-frame.Entry)
+		if !more {
+			return
+		}
+	}
+}
+
+// SyncMarker is an enum type that represents markers that may be
+// written to export data to ensure the reader and writer stay
+// synchronized.
+type SyncMarker int
+
+//go:generate stringer -type=SyncMarker -trimprefix=Sync
+
+const (
+	_ SyncMarker = iota
+
+	// Public markers (known to go/types importers).
+
+	// Low-level coding markers.
+	SyncEOF
+	SyncBool
+	SyncInt64
+	SyncUint64
+	SyncString
+	SyncValue
+	SyncVal
+	SyncRelocs
+	SyncReloc
+	SyncUseReloc
+
+	// Higher-level object and type markers.
+	SyncPublic
+	SyncPos
+	SyncPosBase
+	SyncObject
+	SyncObject1
+	SyncPkg
+	SyncPkgDef
+	SyncMethod
+	SyncType
+	SyncTypeIdx
+	SyncTypeParamNames
+	SyncSignature
+	SyncParams
+	SyncParam
+	SyncCodeObj
+	SyncSym
+	SyncLocalIdent
+	SyncSelector
+
+	// Private markers (only known to cmd/compile).
+	SyncPrivate
+
+	SyncFuncExt
+	SyncVarExt
+	SyncTypeExt
+	SyncPragma
+
+	SyncExprList
+	SyncExprs
+	SyncExpr
+	SyncExprType
+	SyncAssign
+	SyncOp
+	SyncFuncLit
+	SyncCompLit
+
+	SyncDecl
+	SyncFuncBody
+	SyncOpenScope
+	SyncCloseScope
+	SyncCloseAnotherScope
+	SyncDeclNames
+	SyncDeclName
+
+	SyncStmts
+	SyncBlockStmt
+	SyncIfStmt
+	SyncForStmt
+	SyncSwitchStmt
+	SyncRangeStmt
+	SyncCaseClause
+	SyncCommClause
+	SyncSelectStmt
+	SyncDecls
+	SyncLabeledStmt
+	SyncUseObjLocal
+	SyncAddLocal
+	SyncLinkname
+	SyncStmt1
+	SyncStmtsEnd
+	SyncLabel
+	SyncOptLabel
+
+	SyncMultiExpr
+	SyncRType
+	SyncConvRTTI
+)
diff --git a/contrib/go/_std_1.20/src/internal/pkgbits/syncmarker_string.go b/contrib/go/_std_1.20/src/internal/pkgbits/syncmarker_string.go
new file mode 100644
index 0000000000..4a5b0ca5f2
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/pkgbits/syncmarker_string.go
@@ -0,0 +1,89 @@
+// Code generated by "stringer -type=SyncMarker -trimprefix=Sync"; DO NOT EDIT.
+
+package pkgbits
+
+import "strconv"
+
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[SyncEOF-1]
+	_ = x[SyncBool-2]
+	_ = x[SyncInt64-3]
+	_ = x[SyncUint64-4]
+	_ = x[SyncString-5]
+	_ = x[SyncValue-6]
+	_ = x[SyncVal-7]
+	_ = x[SyncRelocs-8]
+	_ = x[SyncReloc-9]
+	_ = x[SyncUseReloc-10]
+	_ = x[SyncPublic-11]
+	_ = x[SyncPos-12]
+	_ = x[SyncPosBase-13]
+	_ = x[SyncObject-14]
+	_ = x[SyncObject1-15]
+	_ = x[SyncPkg-16]
+	_ = x[SyncPkgDef-17]
+	_ = x[SyncMethod-18]
+	_ = x[SyncType-19]
+	_ = x[SyncTypeIdx-20]
+	_ = x[SyncTypeParamNames-21]
+	_ = x[SyncSignature-22]
+	_ = x[SyncParams-23]
+	_ = x[SyncParam-24]
+	_ = x[SyncCodeObj-25]
+	_ = x[SyncSym-26]
+	_ = x[SyncLocalIdent-27]
+	_ = x[SyncSelector-28]
+	_ = x[SyncPrivate-29]
+	_ = x[SyncFuncExt-30]
+	_ = x[SyncVarExt-31]
+	_ = x[SyncTypeExt-32]
+	_ = x[SyncPragma-33]
+	_ = x[SyncExprList-34]
+	_ = x[SyncExprs-35]
+	_ = x[SyncExpr-36]
+	_ = x[SyncExprType-37]
+	_ = x[SyncAssign-38]
+	_ = x[SyncOp-39]
+	_ = x[SyncFuncLit-40]
+	_ = x[SyncCompLit-41]
+	_ = x[SyncDecl-42]
+	_ = x[SyncFuncBody-43]
+	_ = x[SyncOpenScope-44]
+	_ = x[SyncCloseScope-45]
+	_ = x[SyncCloseAnotherScope-46]
+	_ = x[SyncDeclNames-47]
+	_ = x[SyncDeclName-48]
+	_ = x[SyncStmts-49]
+	_ = x[SyncBlockStmt-50]
+	_ = x[SyncIfStmt-51]
+	_ = x[SyncForStmt-52]
+	_ = x[SyncSwitchStmt-53]
+	_ = x[SyncRangeStmt-54]
+	_ = x[SyncCaseClause-55]
+	_ = x[SyncCommClause-56]
+	_ = x[SyncSelectStmt-57]
+	_ = x[SyncDecls-58]
+	_ = x[SyncLabeledStmt-59]
+	_ = x[SyncUseObjLocal-60]
+	_ = x[SyncAddLocal-61]
+	_ = x[SyncLinkname-62]
+	_ = x[SyncStmt1-63]
+	_ = x[SyncStmtsEnd-64]
+	_ = x[SyncLabel-65]
+	_ = x[SyncOptLabel-66]
+}
+
+const _SyncMarker_name = "EOFBoolInt64Uint64StringValueValRelocsRelocUseRelocPublicPosPosBaseObjectObject1PkgPkgDefMethodTypeTypeIdxTypeParamNamesSignatureParamsParamCodeObjSymLocalIdentSelectorPrivateFuncExtVarExtTypeExtPragmaExprListExprsExprExprTypeAssignOpFuncLitCompLitDeclFuncBodyOpenScopeCloseScopeCloseAnotherScopeDeclNamesDeclNameStmtsBlockStmtIfStmtForStmtSwitchStmtRangeStmtCaseClauseCommClauseSelectStmtDeclsLabeledStmtUseObjLocalAddLocalLinknameStmt1StmtsEndLabelOptLabel"
+
+var _SyncMarker_index = [...]uint16{0, 3, 7, 12, 18, 24, 29, 32, 38, 43, 51, 57, 60, 67, 73, 80, 83, 89, 95, 99, 106, 120, 129, 135, 140, 147, 150, 160, 168, 175, 182, 188, 195, 201, 209, 214, 218, 226, 232, 234, 241, 248, 252, 260, 269, 279, 296, 305, 313, 318, 327, 333, 340, 350, 359, 369, 379, 389, 394, 405, 416, 424, 432, 437, 445, 450, 458}
+
+func (i SyncMarker) String() string {
+	i -= 1
+	if i < 0 || i >= SyncMarker(len(_SyncMarker_index)-1) {
+		return "SyncMarker(" + strconv.FormatInt(int64(i+1), 10) + ")"
+	}
+	return _SyncMarker_name[_SyncMarker_index[i]:_SyncMarker_index[i+1]]
+}
diff --git a/contrib/go/_std_1.20/src/internal/pkgbits/ya.make b/contrib/go/_std_1.20/src/internal/pkgbits/ya.make
new file mode 100644
index 0000000000..977ae560cd
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/pkgbits/ya.make
@@ -0,0 +1,15 @@
+GO_LIBRARY()
+
+SRCS(
+    codes.go
+    decoder.go
+    doc.go
+    encoder.go
+    flags.go
+    reloc.go
+    support.go
+    sync.go
+    syncmarker_string.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/poll/copy_file_range_linux.go b/contrib/go/_std_1.20/src/internal/poll/copy_file_range_linux.go
new file mode 100644
index 0000000000..ba33f5145d
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/copy_file_range_linux.go
@@ -0,0 +1,128 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package poll
+
+import (
+	"internal/syscall/unix"
+	"sync"
+	"syscall"
+)
+
+var (
+	kernelVersion53Once sync.Once
+	kernelVersion53     bool
+)
+
+const maxCopyFileRangeRound = 1 << 30
+
+// CopyFileRange copies at most remain bytes of data from src to dst, using
+// the copy_file_range system call. dst and src must refer to regular files.
+func CopyFileRange(dst, src *FD, remain int64) (written int64, handled bool, err error) {
+	kernelVersion53Once.Do(func() {
+		major, minor := unix.KernelVersion()
+		// copy_file_range(2) is broken in various ways on kernels older than 5.3,
+		// see issue #42400 and
+		// https://man7.org/linux/man-pages/man2/copy_file_range.2.html#VERSIONS
+		if major > 5 || (major == 5 && minor >= 3) {
+			kernelVersion53 = true
+		}
+	})
+
+	if !kernelVersion53 {
+		return 0, false, nil
+	}
+
+	for remain > 0 {
+		max := remain
+		if max > maxCopyFileRangeRound {
+			max = maxCopyFileRangeRound
+		}
+		n, err := copyFileRange(dst, src, int(max))
+		switch err {
+		case syscall.ENOSYS:
+			// copy_file_range(2) was introduced in Linux 4.5.
+			// Go supports Linux >= 2.6.33, so the system call
+			// may not be present.
+			//
+			// If we see ENOSYS, we have certainly not transferred
+			// any data, so we can tell the caller that we
+			// couldn't handle the transfer and let them fall
+			// back to more generic code.
+			return 0, false, nil
+		case syscall.EXDEV, syscall.EINVAL, syscall.EIO, syscall.EOPNOTSUPP, syscall.EPERM:
+			// Prior to Linux 5.3, it was not possible to
+			// copy_file_range across file systems. Similarly to
+			// the ENOSYS case above, if we see EXDEV, we have
+			// not transferred any data, and we can let the caller
+			// fall back to generic code.
+			//
+			// As for EINVAL, that is what we see if, for example,
+			// dst or src refer to a pipe rather than a regular
+			// file. This is another case where no data has been
+			// transferred, so we consider it unhandled.
+			//
+			// If src and dst are on CIFS, we can see EIO.
+			// See issue #42334.
+			//
+			// If the file is on NFS, we can see EOPNOTSUPP.
+			// See issue #40731.
+			//
+			// If the process is running inside a Docker container,
+			// we might see EPERM instead of ENOSYS. See issue
+			// #40893. Since EPERM might also be a legitimate error,
+			// don't mark copy_file_range(2) as unsupported.
+			return 0, false, nil
+		case nil:
+			if n == 0 {
+				// If we did not read any bytes at all,
+				// then this file may be in a file system
+				// where copy_file_range silently fails.
+				// https://lore.kernel.org/linux-fsdevel/20210126233840.GG4626@dread.disaster.area/T/#m05753578c7f7882f6e9ffe01f981bc223edef2b0
+				if written == 0 {
+					return 0, false, nil
+				}
+				// Otherwise src is at EOF, which means
+				// we are done.
+				return written, true, nil
+			}
+			remain -= n
+			written += n
+		default:
+			return written, true, err
+		}
+	}
+	return written, true, nil
+}
+
+// copyFileRange performs one round of copy_file_range(2).
+func copyFileRange(dst, src *FD, max int) (written int64, err error) {
+	// The signature of copy_file_range(2) is:
+	//
+	// ssize_t copy_file_range(int fd_in, loff_t *off_in,
+	//                         int fd_out, loff_t *off_out,
+	//                         size_t len, unsigned int flags);
+	//
+	// Note that in the call to unix.CopyFileRange below, we use nil
+	// values for off_in and off_out. For the system call, this means
+	// "use and update the file offsets". That is why we must acquire
+	// locks for both file descriptors (and why this whole machinery is
+	// in the internal/poll package to begin with).
+	if err := dst.writeLock(); err != nil {
+		return 0, err
+	}
+	defer dst.writeUnlock()
+	if err := src.readLock(); err != nil {
+		return 0, err
+	}
+	defer src.readUnlock()
+	var n int
+	for {
+		n, err = unix.CopyFileRange(src.Sysfd, nil, dst.Sysfd, nil, max, 0)
+		if err != syscall.EINTR {
+			break
+		}
+	}
+	return int64(n), err
+}
diff --git a/contrib/go/_std_1.20/src/internal/poll/errno_unix.go b/contrib/go/_std_1.20/src/internal/poll/errno_unix.go
new file mode 100644
index 0000000000..8eed93a31c
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/errno_unix.go
@@ -0,0 +1,33 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build unix
+
+package poll
+
+import "syscall"
+
+// Do the interface allocations only once for common
+// Errno values.
+var (
+	errEAGAIN error = syscall.EAGAIN
+	errEINVAL error = syscall.EINVAL
+	errENOENT error = syscall.ENOENT
+)
+
+// errnoErr returns common boxed Errno values, to prevent
+// allocations at runtime.
+func errnoErr(e syscall.Errno) error {
+	switch e {
+	case 0:
+		return nil
+	case syscall.EAGAIN:
+		return errEAGAIN
+	case syscall.EINVAL:
+		return errEINVAL
+	case syscall.ENOENT:
+		return errENOENT
+	}
+	return e
+}
diff --git a/contrib/go/_std_1.20/src/internal/poll/errno_windows.go b/contrib/go/_std_1.20/src/internal/poll/errno_windows.go
new file mode 100644
index 0000000000..63814793fd
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/errno_windows.go
@@ -0,0 +1,31 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build windows
+
+package poll
+
+import "syscall"
+
+// Do the interface allocations only once for common
+// Errno values.
+
+var (
+	errERROR_IO_PENDING error = syscall.Errno(syscall.ERROR_IO_PENDING)
+)
+
+// errnoErr returns common boxed Errno values, to prevent
+// allocations at runtime.
+func errnoErr(e syscall.Errno) error {
+	switch e {
+	case 0:
+		return nil
+	case syscall.ERROR_IO_PENDING:
+		return errERROR_IO_PENDING
+	}
+	// TODO: add more here, after collecting data on the common
+	// error values see on Windows. (perhaps when running
+	// all.bat?)
+	return e
+}
diff --git a/contrib/go/_std_1.20/src/internal/poll/fcntl_libc.go b/contrib/go/_std_1.20/src/internal/poll/fcntl_libc.go
new file mode 100644
index 0000000000..3f0b6d1bad
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/fcntl_libc.go
@@ -0,0 +1,15 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build aix || darwin || (openbsd && !mips64) || solaris
+
+package poll
+
+import _ "unsafe"
+// for go:linkname
+
+// Implemented in the syscall package.
+//
+//go:linkname fcntl syscall.fcntl
+func fcntl(fd int, cmd int, arg int) (int, error)
diff --git a/contrib/go/_std_1.20/src/internal/poll/fcntl_syscall.go b/contrib/go/_std_1.20/src/internal/poll/fcntl_syscall.go
new file mode 100644
index 0000000000..bbfc8a8be5
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/fcntl_syscall.go
@@ -0,0 +1,20 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build dragonfly || freebsd || linux || netbsd || (openbsd && mips64)
+
+package poll
+
+import (
+	"internal/syscall/unix"
+	"syscall"
+)
+
+func fcntl(fd int, cmd int, arg int) (int, error) {
+	r, _, e := syscall.Syscall(unix.FcntlSyscall, uintptr(fd), uintptr(cmd), uintptr(arg))
+	if e != 0 {
+		return int(r), syscall.Errno(e)
+	}
+	return int(r), nil
+}
diff --git a/contrib/go/_std_1.20/src/internal/poll/fd.go b/contrib/go/_std_1.20/src/internal/poll/fd.go
new file mode 100644
index 0000000000..ef61d0cb3f
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/fd.go
@@ -0,0 +1,83 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package poll supports non-blocking I/O on file descriptors with polling.
+// This supports I/O operations that block only a goroutine, not a thread.
+// This is used by the net and os packages.
+// It uses a poller built into the runtime, with support from the
+// runtime scheduler.
+package poll
+
+import (
+	"errors"
+)
+
+// errNetClosing is the type of the variable ErrNetClosing.
+// This is used to implement the net.Error interface.
+type errNetClosing struct{}
+
+// Error returns the error message for ErrNetClosing.
+// Keep this string consistent because of issue #4373:
+// since historically programs have not been able to detect
+// this error, they look for the string.
+func (e errNetClosing) Error() string { return "use of closed network connection" }
+
+func (e errNetClosing) Timeout() bool   { return false }
+func (e errNetClosing) Temporary() bool { return false }
+
+// ErrNetClosing is returned when a network descriptor is used after
+// it has been closed.
+var ErrNetClosing = errNetClosing{}
+
+// ErrFileClosing is returned when a file descriptor is used after it
+// has been closed.
+var ErrFileClosing = errors.New("use of closed file")
+
+// ErrNoDeadline is returned when a request is made to set a deadline
+// on a file type that does not use the poller.
+var ErrNoDeadline = errors.New("file type does not support deadline")
+
+// Return the appropriate closing error based on isFile.
+func errClosing(isFile bool) error {
+	if isFile {
+		return ErrFileClosing
+	}
+	return ErrNetClosing
+}
+
+// ErrDeadlineExceeded is returned for an expired deadline.
+// This is exported by the os package as os.ErrDeadlineExceeded.
+var ErrDeadlineExceeded error = &DeadlineExceededError{}
+
+// DeadlineExceededError is returned for an expired deadline.
+type DeadlineExceededError struct{}
+
+// Implement the net.Error interface.
+// The string is "i/o timeout" because that is what was returned
+// by earlier Go versions. Changing it may break programs that
+// match on error strings.
+func (e *DeadlineExceededError) Error() string   { return "i/o timeout" }
+func (e *DeadlineExceededError) Timeout() bool   { return true }
+func (e *DeadlineExceededError) Temporary() bool { return true }
+
+// ErrNotPollable is returned when the file or socket is not suitable
+// for event notification.
+var ErrNotPollable = errors.New("not pollable")
+
+// consume removes data from a slice of byte slices, for writev.
+func consume(v *[][]byte, n int64) {
+	for len(*v) > 0 {
+		ln0 := int64(len((*v)[0]))
+		if ln0 > n {
+			(*v)[0] = (*v)[0][n:]
+			return
+		}
+		n -= ln0
+		(*v)[0] = nil
+		*v = (*v)[1:]
+	}
+}
+
+// TestHookDidWritev is a hook for testing writev.
+var TestHookDidWritev = func(wrote int) {}
diff --git a/contrib/go/_std_1.20/src/internal/poll/fd_fsync_darwin.go b/contrib/go/_std_1.20/src/internal/poll/fd_fsync_darwin.go
new file mode 100644
index 0000000000..48e7596922
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/fd_fsync_darwin.go
@@ -0,0 +1,21 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package poll
+
+import "syscall"
+
+// Fsync invokes SYS_FCNTL with SYS_FULLFSYNC because
+// on OS X, SYS_FSYNC doesn't fully flush contents to disk.
+// See Issue #26650 as well as the man page for fsync on OS X.
+func (fd *FD) Fsync() error {
+	if err := fd.incref(); err != nil {
+		return err
+	}
+	defer fd.decref()
+	return ignoringEINTR(func() error {
+		_, err := fcntl(fd.Sysfd, syscall.F_FULLFSYNC, 0)
+		return err
+	})
+}
diff --git a/contrib/go/_std_1.20/src/internal/poll/fd_fsync_posix.go b/contrib/go/_std_1.20/src/internal/poll/fd_fsync_posix.go
new file mode 100644
index 0000000000..6f17019e73
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/fd_fsync_posix.go
@@ -0,0 +1,20 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build aix || dragonfly || freebsd || (js && wasm) || linux || netbsd || openbsd || solaris
+
+package poll
+
+import "syscall"
+
+// Fsync wraps syscall.Fsync.
+func (fd *FD) Fsync() error {
+	if err := fd.incref(); err != nil {
+		return err
+	}
+	defer fd.decref()
+	return ignoringEINTR(func() error {
+		return syscall.Fsync(fd.Sysfd)
+	})
+}
diff --git a/contrib/go/_std_1.20/src/internal/poll/fd_fsync_windows.go b/contrib/go/_std_1.20/src/internal/poll/fd_fsync_windows.go
new file mode 100644
index 0000000000..fb1211985d
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/fd_fsync_windows.go
@@ -0,0 +1,16 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package poll
+
+import "syscall"
+
+// Fsync wraps syscall.Fsync.
+func (fd *FD) Fsync() error {
+	if err := fd.incref(); err != nil {
+		return err
+	}
+	defer fd.decref()
+	return syscall.Fsync(fd.Sysfd)
+}
diff --git a/contrib/go/_std_1.20/src/internal/poll/fd_mutex.go b/contrib/go/_std_1.20/src/internal/poll/fd_mutex.go
new file mode 100644
index 0000000000..0a8ee6f0d4
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/fd_mutex.go
@@ -0,0 +1,252 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package poll
+
+import "sync/atomic"
+
+// fdMutex is a specialized synchronization primitive that manages
+// lifetime of an fd and serializes access to Read, Write and Close
+// methods on FD.
+type fdMutex struct {
+	state uint64
+	rsema uint32
+	wsema uint32
+}
+
+// fdMutex.state is organized as follows:
+// 1 bit - whether FD is closed, if set all subsequent lock operations will fail.
+// 1 bit - lock for read operations.
+// 1 bit - lock for write operations.
+// 20 bits - total number of references (read+write+misc).
+// 20 bits - number of outstanding read waiters.
+// 20 bits - number of outstanding write waiters.
+const (
+	mutexClosed  = 1 << 0
+	mutexRLock   = 1 << 1
+	mutexWLock   = 1 << 2
+	mutexRef     = 1 << 3
+	mutexRefMask = (1<<20 - 1) << 3
+	mutexRWait   = 1 << 23
+	mutexRMask   = (1<<20 - 1) << 23
+	mutexWWait   = 1 << 43
+	mutexWMask   = (1<<20 - 1) << 43
+)
+
+const overflowMsg = "too many concurrent operations on a single file or socket (max 1048575)"
+
+// Read operations must do rwlock(true)/rwunlock(true).
+//
+// Write operations must do rwlock(false)/rwunlock(false).
+//
+// Misc operations must do incref/decref.
+// Misc operations include functions like setsockopt and setDeadline.
+// They need to use incref/decref to ensure that they operate on the
+// correct fd in presence of a concurrent close call (otherwise fd can
+// be closed under their feet).
+//
+// Close operations must do increfAndClose/decref.
+
+// incref adds a reference to mu.
+// It reports whether mu is available for reading or writing.
+func (mu *fdMutex) incref() bool {
+	for {
+		old := atomic.LoadUint64(&mu.state)
+		if old&mutexClosed != 0 {
+			return false
+		}
+		new := old + mutexRef
+		if new&mutexRefMask == 0 {
+			panic(overflowMsg)
+		}
+		if atomic.CompareAndSwapUint64(&mu.state, old, new) {
+			return true
+		}
+	}
+}
+
+// increfAndClose sets the state of mu to closed.
+// It returns false if the file was already closed.
+func (mu *fdMutex) increfAndClose() bool {
+	for {
+		old := atomic.LoadUint64(&mu.state)
+		if old&mutexClosed != 0 {
+			return false
+		}
+		// Mark as closed and acquire a reference.
+		new := (old | mutexClosed) + mutexRef
+		if new&mutexRefMask == 0 {
+			panic(overflowMsg)
+		}
+		// Remove all read and write waiters.
+		new &^= mutexRMask | mutexWMask
+		if atomic.CompareAndSwapUint64(&mu.state, old, new) {
+			// Wake all read and write waiters,
+			// they will observe closed flag after wakeup.
+			for old&mutexRMask != 0 {
+				old -= mutexRWait
+				runtime_Semrelease(&mu.rsema)
+			}
+			for old&mutexWMask != 0 {
+				old -= mutexWWait
+				runtime_Semrelease(&mu.wsema)
+			}
+			return true
+		}
+	}
+}
+
+// decref removes a reference from mu.
+// It reports whether there is no remaining reference.
+func (mu *fdMutex) decref() bool {
+	for {
+		old := atomic.LoadUint64(&mu.state)
+		if old&mutexRefMask == 0 {
+			panic("inconsistent poll.fdMutex")
+		}
+		new := old - mutexRef
+		if atomic.CompareAndSwapUint64(&mu.state, old, new) {
+			return new&(mutexClosed|mutexRefMask) == mutexClosed
+		}
+	}
+}
+
+// lock adds a reference to mu and locks mu.
+// It reports whether mu is available for reading or writing.
+func (mu *fdMutex) rwlock(read bool) bool {
+	var mutexBit, mutexWait, mutexMask uint64
+	var mutexSema *uint32
+	if read {
+		mutexBit = mutexRLock
+		mutexWait = mutexRWait
+		mutexMask = mutexRMask
+		mutexSema = &mu.rsema
+	} else {
+		mutexBit = mutexWLock
+		mutexWait = mutexWWait
+		mutexMask = mutexWMask
+		mutexSema = &mu.wsema
+	}
+	for {
+		old := atomic.LoadUint64(&mu.state)
+		if old&mutexClosed != 0 {
+			return false
+		}
+		var new uint64
+		if old&mutexBit == 0 {
+			// Lock is free, acquire it.
+			new = (old | mutexBit) + mutexRef
+			if new&mutexRefMask == 0 {
+				panic(overflowMsg)
+			}
+		} else {
+			// Wait for lock.
+			new = old + mutexWait
+			if new&mutexMask == 0 {
+				panic(overflowMsg)
+			}
+		}
+		if atomic.CompareAndSwapUint64(&mu.state, old, new) {
+			if old&mutexBit == 0 {
+				return true
+			}
+			runtime_Semacquire(mutexSema)
+			// The signaller has subtracted mutexWait.
+		}
+	}
+}
+
+// unlock removes a reference from mu and unlocks mu.
+// It reports whether there is no remaining reference.
+func (mu *fdMutex) rwunlock(read bool) bool {
+	var mutexBit, mutexWait, mutexMask uint64
+	var mutexSema *uint32
+	if read {
+		mutexBit = mutexRLock
+		mutexWait = mutexRWait
+		mutexMask = mutexRMask
+		mutexSema = &mu.rsema
+	} else {
+		mutexBit = mutexWLock
+		mutexWait = mutexWWait
+		mutexMask = mutexWMask
+		mutexSema = &mu.wsema
+	}
+	for {
+		old := atomic.LoadUint64(&mu.state)
+		if old&mutexBit == 0 || old&mutexRefMask == 0 {
+			panic("inconsistent poll.fdMutex")
+		}
+		// Drop lock, drop reference and wake read waiter if present.
+		new := (old &^ mutexBit) - mutexRef
+		if old&mutexMask != 0 {
+			new -= mutexWait
+		}
+		if atomic.CompareAndSwapUint64(&mu.state, old, new) {
+			if old&mutexMask != 0 {
+				runtime_Semrelease(mutexSema)
+			}
+			return new&(mutexClosed|mutexRefMask) == mutexClosed
+		}
+	}
+}
+
+// Implemented in runtime package.
+func runtime_Semacquire(sema *uint32)
+func runtime_Semrelease(sema *uint32)
+
+// incref adds a reference to fd.
+// It returns an error when fd cannot be used.
+func (fd *FD) incref() error {
+	if !fd.fdmu.incref() {
+		return errClosing(fd.isFile)
+	}
+	return nil
+}
+
+// decref removes a reference from fd.
+// It also closes fd when the state of fd is set to closed and there
+// is no remaining reference.
+func (fd *FD) decref() error {
+	if fd.fdmu.decref() {
+		return fd.destroy()
+	}
+	return nil
+}
+
+// readLock adds a reference to fd and locks fd for reading.
+// It returns an error when fd cannot be used for reading.
+func (fd *FD) readLock() error {
+	if !fd.fdmu.rwlock(true) {
+		return errClosing(fd.isFile)
+	}
+	return nil
+}
+
+// readUnlock removes a reference from fd and unlocks fd for reading.
+// It also closes fd when the state of fd is set to closed and there
+// is no remaining reference.
+func (fd *FD) readUnlock() {
+	if fd.fdmu.rwunlock(true) {
+		fd.destroy()
+	}
+}
+
+// writeLock adds a reference to fd and locks fd for writing.
+// It returns an error when fd cannot be used for writing.
+func (fd *FD) writeLock() error {
+	if !fd.fdmu.rwlock(false) {
+		return errClosing(fd.isFile)
+	}
+	return nil
+}
+
+// writeUnlock removes a reference from fd and unlocks fd for writing.
+// It also closes fd when the state of fd is set to closed and there
+// is no remaining reference.
+func (fd *FD) writeUnlock() {
+	if fd.fdmu.rwunlock(false) {
+		fd.destroy()
+	}
+}
diff --git a/contrib/go/_std_1.20/src/internal/poll/fd_opendir_darwin.go b/contrib/go/_std_1.20/src/internal/poll/fd_opendir_darwin.go
new file mode 100644
index 0000000000..81cfb29079
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/fd_opendir_darwin.go
@@ -0,0 +1,40 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package poll
+
+import (
+	"syscall"
+	_ "unsafe" // for go:linkname
+
+)
+
+// OpenDir returns a pointer to a DIR structure suitable for
+// ReadDir. In case of an error, the name of the failed
+// syscall is returned along with a syscall.Errno.
+func (fd *FD) OpenDir() (uintptr, string, error) {
+	// fdopendir(3) takes control of the file descriptor,
+	// so use a dup.
+	fd2, call, err := fd.Dup()
+	if err != nil {
+		return 0, call, err
+	}
+	var dir uintptr
+	for {
+		dir, err = fdopendir(fd2)
+		if err != syscall.EINTR {
+			break
+		}
+	}
+	if err != nil {
+		syscall.Close(fd2)
+		return 0, "fdopendir", err
+	}
+	return dir, "", nil
+}
+
+// Implemented in syscall/syscall_darwin.go.
+//
+//go:linkname fdopendir syscall.fdopendir
+func fdopendir(fd int) (dir uintptr, err error)
diff --git a/contrib/go/_std_1.20/src/internal/poll/fd_poll_runtime.go b/contrib/go/_std_1.20/src/internal/poll/fd_poll_runtime.go
new file mode 100644
index 0000000000..6fc627db32
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/fd_poll_runtime.go
@@ -0,0 +1,170 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build unix || windows
+
+package poll
+
+import (
+	"errors"
+	"sync"
+	"syscall"
+	"time"
+	_ "unsafe" // for go:linkname
+
+)
+
+// runtimeNano returns the current value of the runtime clock in nanoseconds.
+//
+//go:linkname runtimeNano runtime.nanotime
+func runtimeNano() int64
+
+func runtime_pollServerInit()
+func runtime_pollOpen(fd uintptr) (uintptr, int)
+func runtime_pollClose(ctx uintptr)
+func runtime_pollWait(ctx uintptr, mode int) int
+func runtime_pollWaitCanceled(ctx uintptr, mode int)
+func runtime_pollReset(ctx uintptr, mode int) int
+func runtime_pollSetDeadline(ctx uintptr, d int64, mode int)
+func runtime_pollUnblock(ctx uintptr)
+func runtime_isPollServerDescriptor(fd uintptr) bool
+
+type pollDesc struct {
+	runtimeCtx uintptr
+}
+
+var serverInit sync.Once
+
+func (pd *pollDesc) init(fd *FD) error {
+	serverInit.Do(runtime_pollServerInit)
+	ctx, errno := runtime_pollOpen(uintptr(fd.Sysfd))
+	if errno != 0 {
+		return errnoErr(syscall.Errno(errno))
+	}
+	pd.runtimeCtx = ctx
+	return nil
+}
+
+func (pd *pollDesc) close() {
+	if pd.runtimeCtx == 0 {
+		return
+	}
+	runtime_pollClose(pd.runtimeCtx)
+	pd.runtimeCtx = 0
+}
+
+// Evict evicts fd from the pending list, unblocking any I/O running on fd.
+func (pd *pollDesc) evict() {
+	if pd.runtimeCtx == 0 {
+		return
+	}
+	runtime_pollUnblock(pd.runtimeCtx)
+}
+
+func (pd *pollDesc) prepare(mode int, isFile bool) error {
+	if pd.runtimeCtx == 0 {
+		return nil
+	}
+	res := runtime_pollReset(pd.runtimeCtx, mode)
+	return convertErr(res, isFile)
+}
+
+func (pd *pollDesc) prepareRead(isFile bool) error {
+	return pd.prepare('r', isFile)
+}
+
+func (pd *pollDesc) prepareWrite(isFile bool) error {
+	return pd.prepare('w', isFile)
+}
+
+func (pd *pollDesc) wait(mode int, isFile bool) error {
+	if pd.runtimeCtx == 0 {
+		return errors.New("waiting for unsupported file type")
+	}
+	res := runtime_pollWait(pd.runtimeCtx, mode)
+	return convertErr(res, isFile)
+}
+
+func (pd *pollDesc) waitRead(isFile bool) error {
+	return pd.wait('r', isFile)
+}
+
+func (pd *pollDesc) waitWrite(isFile bool) error {
+	return pd.wait('w', isFile)
+}
+
+func (pd *pollDesc) waitCanceled(mode int) {
+	if pd.runtimeCtx == 0 {
+		return
+	}
+	runtime_pollWaitCanceled(pd.runtimeCtx, mode)
+}
+
+func (pd *pollDesc) pollable() bool {
+	return pd.runtimeCtx != 0
+}
+
+// Error values returned by runtime_pollReset and runtime_pollWait.
+// These must match the values in runtime/netpoll.go.
+const (
+	pollNoError        = 0
+	pollErrClosing     = 1
+	pollErrTimeout     = 2
+	pollErrNotPollable = 3
+)
+
+func convertErr(res int, isFile bool) error {
+	switch res {
+	case pollNoError:
+		return nil
+	case pollErrClosing:
+		return errClosing(isFile)
+	case pollErrTimeout:
+		return ErrDeadlineExceeded
+	case pollErrNotPollable:
+		return ErrNotPollable
+	}
+	println("unreachable: ", res)
+	panic("unreachable")
+}
+
+// SetDeadline sets the read and write deadlines associated with fd.
+func (fd *FD) SetDeadline(t time.Time) error {
+	return setDeadlineImpl(fd, t, 'r'+'w')
+}
+
+// SetReadDeadline sets the read deadline associated with fd.
+func (fd *FD) SetReadDeadline(t time.Time) error {
+	return setDeadlineImpl(fd, t, 'r')
+}
+
+// SetWriteDeadline sets the write deadline associated with fd.
+func (fd *FD) SetWriteDeadline(t time.Time) error {
+	return setDeadlineImpl(fd, t, 'w')
+}
+
+func setDeadlineImpl(fd *FD, t time.Time, mode int) error {
+	var d int64
+	if !t.IsZero() {
+		d = int64(time.Until(t))
+		if d == 0 {
+			d = -1 // don't confuse deadline right now with no deadline
+		}
+	}
+	if err := fd.incref(); err != nil {
+		return err
+	}
+	defer fd.decref()
+	if fd.pd.runtimeCtx == 0 {
+		return ErrNoDeadline
+	}
+	runtime_pollSetDeadline(fd.pd.runtimeCtx, d, mode)
+	return nil
+}
+
+// IsPollDescriptor reports whether fd is the descriptor being used by the poller.
+// This is only used for testing.
+func IsPollDescriptor(fd uintptr) bool {
+	return runtime_isPollServerDescriptor(fd)
+}
diff --git a/contrib/go/_std_1.20/src/internal/poll/fd_posix.go b/contrib/go/_std_1.20/src/internal/poll/fd_posix.go
new file mode 100644
index 0000000000..778fe1e5c1
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/fd_posix.go
@@ -0,0 +1,79 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build unix || (js && wasm) || windows
+
+package poll
+
+import (
+	"io"
+	"syscall"
+)
+
+// eofError returns io.EOF when fd is available for reading end of
+// file.
+func (fd *FD) eofError(n int, err error) error {
+	if n == 0 && err == nil && fd.ZeroReadIsEOF {
+		return io.EOF
+	}
+	return err
+}
+
+// Shutdown wraps syscall.Shutdown.
+func (fd *FD) Shutdown(how int) error {
+	if err := fd.incref(); err != nil {
+		return err
+	}
+	defer fd.decref()
+	return syscall.Shutdown(fd.Sysfd, how)
+}
+
+// Fchown wraps syscall.Fchown.
+func (fd *FD) Fchown(uid, gid int) error {
+	if err := fd.incref(); err != nil {
+		return err
+	}
+	defer fd.decref()
+	return ignoringEINTR(func() error {
+		return syscall.Fchown(fd.Sysfd, uid, gid)
+	})
+}
+
+// Ftruncate wraps syscall.Ftruncate.
+func (fd *FD) Ftruncate(size int64) error {
+	if err := fd.incref(); err != nil {
+		return err
+	}
+	defer fd.decref()
+	return ignoringEINTR(func() error {
+		return syscall.Ftruncate(fd.Sysfd, size)
+	})
+}
+
+// RawControl invokes the user-defined function f for a non-IO
+// operation.
+func (fd *FD) RawControl(f func(uintptr)) error {
+	if err := fd.incref(); err != nil {
+		return err
+	}
+	defer fd.decref()
+	f(uintptr(fd.Sysfd))
+	return nil
+}
+
+// ignoringEINTR makes a function call and repeats it if it returns
+// an EINTR error. This appears to be required even though we install all
+// signal handlers with SA_RESTART: see #22838, #38033, #38836, #40846.
+// Also #20400 and #36644 are issues in which a signal handler is
+// installed without setting SA_RESTART. None of these are the common case,
+// but there are enough of them that it seems that we can't avoid
+// an EINTR loop.
+func ignoringEINTR(fn func() error) error {
+	for {
+		err := fn()
+		if err != syscall.EINTR {
+			return err
+		}
+	}
+}
diff --git a/contrib/go/_std_1.20/src/internal/poll/fd_unix.go b/contrib/go/_std_1.20/src/internal/poll/fd_unix.go
new file mode 100644
index 0000000000..2786064d9f
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/fd_unix.go
@@ -0,0 +1,799 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build unix || (js && wasm)
+
+package poll
+
+import (
+	"internal/syscall/unix"
+	"io"
+	"sync/atomic"
+	"syscall"
+)
+
+// FD is a file descriptor. The net and os packages use this type as a
+// field of a larger type representing a network connection or OS file.
+type FD struct {
+	// Lock sysfd and serialize access to Read and Write methods.
+	fdmu fdMutex
+
+	// System file descriptor. Immutable until Close.
+	Sysfd int
+
+	// I/O poller.
+	pd pollDesc
+
+	// Writev cache.
+	iovecs *[]syscall.Iovec
+
+	// Semaphore signaled when file is closed.
+	csema uint32
+
+	// Non-zero if this file has been set to blocking mode.
+	isBlocking uint32
+
+	// Whether this is a streaming descriptor, as opposed to a
+	// packet-based descriptor like a UDP socket. Immutable.
+	IsStream bool
+
+	// Whether a zero byte read indicates EOF. This is false for a
+	// message based socket connection.
+	ZeroReadIsEOF bool
+
+	// Whether this is a file rather than a network socket.
+	isFile bool
+}
+
+// Init initializes the FD. The Sysfd field should already be set.
+// This can be called multiple times on a single FD.
+// The net argument is a network name from the net package (e.g., "tcp"),
+// or "file".
+// Set pollable to true if fd should be managed by runtime netpoll.
+func (fd *FD) Init(net string, pollable bool) error {
+	// We don't actually care about the various network types.
+	if net == "file" {
+		fd.isFile = true
+	}
+	if !pollable {
+		fd.isBlocking = 1
+		return nil
+	}
+	err := fd.pd.init(fd)
+	if err != nil {
+		// If we could not initialize the runtime poller,
+		// assume we are using blocking mode.
+		fd.isBlocking = 1
+	}
+	return err
+}
+
+// Destroy closes the file descriptor. This is called when there are
+// no remaining references.
+func (fd *FD) destroy() error {
+	// Poller may want to unregister fd in readiness notification mechanism,
+	// so this must be executed before CloseFunc.
+	fd.pd.close()
+
+	// We don't use ignoringEINTR here because POSIX does not define
+	// whether the descriptor is closed if close returns EINTR.
+	// If the descriptor is indeed closed, using a loop would race
+	// with some other goroutine opening a new descriptor.
+	// (The Linux kernel guarantees that it is closed on an EINTR error.)
+	err := CloseFunc(fd.Sysfd)
+
+	fd.Sysfd = -1
+	runtime_Semrelease(&fd.csema)
+	return err
+}
+
+// Close closes the FD. The underlying file descriptor is closed by the
+// destroy method when there are no remaining references.
+func (fd *FD) Close() error {
+	if !fd.fdmu.increfAndClose() {
+		return errClosing(fd.isFile)
+	}
+
+	// Unblock any I/O.  Once it all unblocks and returns,
+	// so that it cannot be referring to fd.sysfd anymore,
+	// the final decref will close fd.sysfd. This should happen
+	// fairly quickly, since all the I/O is non-blocking, and any
+	// attempts to block in the pollDesc will return errClosing(fd.isFile).
+	fd.pd.evict()
+
+	// The call to decref will call destroy if there are no other
+	// references.
+	err := fd.decref()
+
+	// Wait until the descriptor is closed. If this was the only
+	// reference, it is already closed. Only wait if the file has
+	// not been set to blocking mode, as otherwise any current I/O
+	// may be blocking, and that would block the Close.
+	// No need for an atomic read of isBlocking, increfAndClose means
+	// we have exclusive access to fd.
+	if fd.isBlocking == 0 {
+		runtime_Semacquire(&fd.csema)
+	}
+
+	return err
+}
+
+// SetBlocking puts the file into blocking mode.
+func (fd *FD) SetBlocking() error {
+	if err := fd.incref(); err != nil {
+		return err
+	}
+	defer fd.decref()
+	// Atomic store so that concurrent calls to SetBlocking
+	// do not cause a race condition. isBlocking only ever goes
+	// from 0 to 1 so there is no real race here.
+	atomic.StoreUint32(&fd.isBlocking, 1)
+	return syscall.SetNonblock(fd.Sysfd, false)
+}
+
+// Darwin and FreeBSD can't read or write 2GB+ files at a time,
+// even on 64-bit systems.
+// The same is true of socket implementations on many systems.
+// See golang.org/issue/7812 and golang.org/issue/16266.
+// Use 1GB instead of, say, 2GB-1, to keep subsequent reads aligned.
+const maxRW = 1 << 30
+
+// Read implements io.Reader.
+func (fd *FD) Read(p []byte) (int, error) {
+	if err := fd.readLock(); err != nil {
+		return 0, err
+	}
+	defer fd.readUnlock()
+	if len(p) == 0 {
+		// If the caller wanted a zero byte read, return immediately
+		// without trying (but after acquiring the readLock).
+		// Otherwise syscall.Read returns 0, nil which looks like
+		// io.EOF.
+		// TODO(bradfitz): make it wait for readability? (Issue 15735)
+		return 0, nil
+	}
+	if err := fd.pd.prepareRead(fd.isFile); err != nil {
+		return 0, err
+	}
+	if fd.IsStream && len(p) > maxRW {
+		p = p[:maxRW]
+	}
+	for {
+		n, err := ignoringEINTRIO(syscall.Read, fd.Sysfd, p)
+		if err != nil {
+			n = 0
+			if err == syscall.EAGAIN && fd.pd.pollable() {
+				if err = fd.pd.waitRead(fd.isFile); err == nil {
+					continue
+				}
+			}
+		}
+		err = fd.eofError(n, err)
+		return n, err
+	}
+}
+
+// Pread wraps the pread system call.
+func (fd *FD) Pread(p []byte, off int64) (int, error) {
+	// Call incref, not readLock, because since pread specifies the
+	// offset it is independent from other reads.
+	// Similarly, using the poller doesn't make sense for pread.
+	if err := fd.incref(); err != nil {
+		return 0, err
+	}
+	if fd.IsStream && len(p) > maxRW {
+		p = p[:maxRW]
+	}
+	var (
+		n   int
+		err error
+	)
+	for {
+		n, err = syscall.Pread(fd.Sysfd, p, off)
+		if err != syscall.EINTR {
+			break
+		}
+	}
+	if err != nil {
+		n = 0
+	}
+	fd.decref()
+	err = fd.eofError(n, err)
+	return n, err
+}
+
+// ReadFrom wraps the recvfrom network call.
+func (fd *FD) ReadFrom(p []byte) (int, syscall.Sockaddr, error) {
+	if err := fd.readLock(); err != nil {
+		return 0, nil, err
+	}
+	defer fd.readUnlock()
+	if err := fd.pd.prepareRead(fd.isFile); err != nil {
+		return 0, nil, err
+	}
+	for {
+		n, sa, err := syscall.Recvfrom(fd.Sysfd, p, 0)
+		if err != nil {
+			if err == syscall.EINTR {
+				continue
+			}
+			n = 0
+			if err == syscall.EAGAIN && fd.pd.pollable() {
+				if err = fd.pd.waitRead(fd.isFile); err == nil {
+					continue
+				}
+			}
+		}
+		err = fd.eofError(n, err)
+		return n, sa, err
+	}
+}
+
+// ReadFromInet4 wraps the recvfrom network call for IPv4.
+func (fd *FD) ReadFromInet4(p []byte, from *syscall.SockaddrInet4) (int, error) {
+	if err := fd.readLock(); err != nil {
+		return 0, err
+	}
+	defer fd.readUnlock()
+	if err := fd.pd.prepareRead(fd.isFile); err != nil {
+		return 0, err
+	}
+	for {
+		n, err := unix.RecvfromInet4(fd.Sysfd, p, 0, from)
+		if err != nil {
+			if err == syscall.EINTR {
+				continue
+			}
+			n = 0
+			if err == syscall.EAGAIN && fd.pd.pollable() {
+				if err = fd.pd.waitRead(fd.isFile); err == nil {
+					continue
+				}
+			}
+		}
+		err = fd.eofError(n, err)
+		return n, err
+	}
+}
+
+// ReadFromInet6 wraps the recvfrom network call for IPv6.
+func (fd *FD) ReadFromInet6(p []byte, from *syscall.SockaddrInet6) (int, error) {
+	if err := fd.readLock(); err != nil {
+		return 0, err
+	}
+	defer fd.readUnlock()
+	if err := fd.pd.prepareRead(fd.isFile); err != nil {
+		return 0, err
+	}
+	for {
+		n, err := unix.RecvfromInet6(fd.Sysfd, p, 0, from)
+		if err != nil {
+			if err == syscall.EINTR {
+				continue
+			}
+			n = 0
+			if err == syscall.EAGAIN && fd.pd.pollable() {
+				if err = fd.pd.waitRead(fd.isFile); err == nil {
+					continue
+				}
+			}
+		}
+		err = fd.eofError(n, err)
+		return n, err
+	}
+}
+
+// ReadMsg wraps the recvmsg network call.
+func (fd *FD) ReadMsg(p []byte, oob []byte, flags int) (int, int, int, syscall.Sockaddr, error) {
+	if err := fd.readLock(); err != nil {
+		return 0, 0, 0, nil, err
+	}
+	defer fd.readUnlock()
+	if err := fd.pd.prepareRead(fd.isFile); err != nil {
+		return 0, 0, 0, nil, err
+	}
+	for {
+		n, oobn, sysflags, sa, err := syscall.Recvmsg(fd.Sysfd, p, oob, flags)
+		if err != nil {
+			if err == syscall.EINTR {
+				continue
+			}
+			// TODO(dfc) should n and oobn be set to 0
+			if err == syscall.EAGAIN && fd.pd.pollable() {
+				if err = fd.pd.waitRead(fd.isFile); err == nil {
+					continue
+				}
+			}
+		}
+		err = fd.eofError(n, err)
+		return n, oobn, sysflags, sa, err
+	}
+}
+
+// ReadMsgInet4 is ReadMsg, but specialized for syscall.SockaddrInet4.
+func (fd *FD) ReadMsgInet4(p []byte, oob []byte, flags int, sa4 *syscall.SockaddrInet4) (int, int, int, error) {
+	if err := fd.readLock(); err != nil {
+		return 0, 0, 0, err
+	}
+	defer fd.readUnlock()
+	if err := fd.pd.prepareRead(fd.isFile); err != nil {
+		return 0, 0, 0, err
+	}
+	for {
+		n, oobn, sysflags, err := unix.RecvmsgInet4(fd.Sysfd, p, oob, flags, sa4)
+		if err != nil {
+			if err == syscall.EINTR {
+				continue
+			}
+			// TODO(dfc) should n and oobn be set to 0
+			if err == syscall.EAGAIN && fd.pd.pollable() {
+				if err = fd.pd.waitRead(fd.isFile); err == nil {
+					continue
+				}
+			}
+		}
+		err = fd.eofError(n, err)
+		return n, oobn, sysflags, err
+	}
+}
+
+// ReadMsgInet6 is ReadMsg, but specialized for syscall.SockaddrInet6.
+func (fd *FD) ReadMsgInet6(p []byte, oob []byte, flags int, sa6 *syscall.SockaddrInet6) (int, int, int, error) {
+	if err := fd.readLock(); err != nil {
+		return 0, 0, 0, err
+	}
+	defer fd.readUnlock()
+	if err := fd.pd.prepareRead(fd.isFile); err != nil {
+		return 0, 0, 0, err
+	}
+	for {
+		n, oobn, sysflags, err := unix.RecvmsgInet6(fd.Sysfd, p, oob, flags, sa6)
+		if err != nil {
+			if err == syscall.EINTR {
+				continue
+			}
+			// TODO(dfc) should n and oobn be set to 0
+			if err == syscall.EAGAIN && fd.pd.pollable() {
+				if err = fd.pd.waitRead(fd.isFile); err == nil {
+					continue
+				}
+			}
+		}
+		err = fd.eofError(n, err)
+		return n, oobn, sysflags, err
+	}
+}
+
+// Write implements io.Writer.
+func (fd *FD) Write(p []byte) (int, error) {
+	if err := fd.writeLock(); err != nil {
+		return 0, err
+	}
+	defer fd.writeUnlock()
+	if err := fd.pd.prepareWrite(fd.isFile); err != nil {
+		return 0, err
+	}
+	var nn int
+	for {
+		max := len(p)
+		if fd.IsStream && max-nn > maxRW {
+			max = nn + maxRW
+		}
+		n, err := ignoringEINTRIO(syscall.Write, fd.Sysfd, p[nn:max])
+		if n > 0 {
+			nn += n
+		}
+		if nn == len(p) {
+			return nn, err
+		}
+		if err == syscall.EAGAIN && fd.pd.pollable() {
+			if err = fd.pd.waitWrite(fd.isFile); err == nil {
+				continue
+			}
+		}
+		if err != nil {
+			return nn, err
+		}
+		if n == 0 {
+			return nn, io.ErrUnexpectedEOF
+		}
+	}
+}
+
+// Pwrite wraps the pwrite system call.
+func (fd *FD) Pwrite(p []byte, off int64) (int, error) {
+	// Call incref, not writeLock, because since pwrite specifies the
+	// offset it is independent from other writes.
+	// Similarly, using the poller doesn't make sense for pwrite.
+	if err := fd.incref(); err != nil {
+		return 0, err
+	}
+	defer fd.decref()
+	var nn int
+	for {
+		max := len(p)
+		if fd.IsStream && max-nn > maxRW {
+			max = nn + maxRW
+		}
+		n, err := syscall.Pwrite(fd.Sysfd, p[nn:max], off+int64(nn))
+		if err == syscall.EINTR {
+			continue
+		}
+		if n > 0 {
+			nn += n
+		}
+		if nn == len(p) {
+			return nn, err
+		}
+		if err != nil {
+			return nn, err
+		}
+		if n == 0 {
+			return nn, io.ErrUnexpectedEOF
+		}
+	}
+}
+
+// WriteToInet4 wraps the sendto network call for IPv4 addresses.
+func (fd *FD) WriteToInet4(p []byte, sa *syscall.SockaddrInet4) (int, error) {
+	if err := fd.writeLock(); err != nil {
+		return 0, err
+	}
+	defer fd.writeUnlock()
+	if err := fd.pd.prepareWrite(fd.isFile); err != nil {
+		return 0, err
+	}
+	for {
+		err := unix.SendtoInet4(fd.Sysfd, p, 0, sa)
+		if err == syscall.EINTR {
+			continue
+		}
+		if err == syscall.EAGAIN && fd.pd.pollable() {
+			if err = fd.pd.waitWrite(fd.isFile); err == nil {
+				continue
+			}
+		}
+		if err != nil {
+			return 0, err
+		}
+		return len(p), nil
+	}
+}
+
+// WriteToInet6 wraps the sendto network call for IPv6 addresses.
+func (fd *FD) WriteToInet6(p []byte, sa *syscall.SockaddrInet6) (int, error) {
+	if err := fd.writeLock(); err != nil {
+		return 0, err
+	}
+	defer fd.writeUnlock()
+	if err := fd.pd.prepareWrite(fd.isFile); err != nil {
+		return 0, err
+	}
+	for {
+		err := unix.SendtoInet6(fd.Sysfd, p, 0, sa)
+		if err == syscall.EINTR {
+			continue
+		}
+		if err == syscall.EAGAIN && fd.pd.pollable() {
+			if err = fd.pd.waitWrite(fd.isFile); err == nil {
+				continue
+			}
+		}
+		if err != nil {
+			return 0, err
+		}
+		return len(p), nil
+	}
+}
+
+// WriteTo wraps the sendto network call.
+func (fd *FD) WriteTo(p []byte, sa syscall.Sockaddr) (int, error) {
+	if err := fd.writeLock(); err != nil {
+		return 0, err
+	}
+	defer fd.writeUnlock()
+	if err := fd.pd.prepareWrite(fd.isFile); err != nil {
+		return 0, err
+	}
+	for {
+		err := syscall.Sendto(fd.Sysfd, p, 0, sa)
+		if err == syscall.EINTR {
+			continue
+		}
+		if err == syscall.EAGAIN && fd.pd.pollable() {
+			if err = fd.pd.waitWrite(fd.isFile); err == nil {
+				continue
+			}
+		}
+		if err != nil {
+			return 0, err
+		}
+		return len(p), nil
+	}
+}
+
+// WriteMsg wraps the sendmsg network call.
+func (fd *FD) WriteMsg(p []byte, oob []byte, sa syscall.Sockaddr) (int, int, error) {
+	if err := fd.writeLock(); err != nil {
+		return 0, 0, err
+	}
+	defer fd.writeUnlock()
+	if err := fd.pd.prepareWrite(fd.isFile); err != nil {
+		return 0, 0, err
+	}
+	for {
+		n, err := syscall.SendmsgN(fd.Sysfd, p, oob, sa, 0)
+		if err == syscall.EINTR {
+			continue
+		}
+		if err == syscall.EAGAIN && fd.pd.pollable() {
+			if err = fd.pd.waitWrite(fd.isFile); err == nil {
+				continue
+			}
+		}
+		if err != nil {
+			return n, 0, err
+		}
+		return n, len(oob), err
+	}
+}
+
+// WriteMsgInet4 is WriteMsg specialized for syscall.SockaddrInet4.
+func (fd *FD) WriteMsgInet4(p []byte, oob []byte, sa *syscall.SockaddrInet4) (int, int, error) {
+	if err := fd.writeLock(); err != nil {
+		return 0, 0, err
+	}
+	defer fd.writeUnlock()
+	if err := fd.pd.prepareWrite(fd.isFile); err != nil {
+		return 0, 0, err
+	}
+	for {
+		n, err := unix.SendmsgNInet4(fd.Sysfd, p, oob, sa, 0)
+		if err == syscall.EINTR {
+			continue
+		}
+		if err == syscall.EAGAIN && fd.pd.pollable() {
+			if err = fd.pd.waitWrite(fd.isFile); err == nil {
+				continue
+			}
+		}
+		if err != nil {
+			return n, 0, err
+		}
+		return n, len(oob), err
+	}
+}
+
+// WriteMsgInet6 is WriteMsg specialized for syscall.SockaddrInet6.
+func (fd *FD) WriteMsgInet6(p []byte, oob []byte, sa *syscall.SockaddrInet6) (int, int, error) {
+	if err := fd.writeLock(); err != nil {
+		return 0, 0, err
+	}
+	defer fd.writeUnlock()
+	if err := fd.pd.prepareWrite(fd.isFile); err != nil {
+		return 0, 0, err
+	}
+	for {
+		n, err := unix.SendmsgNInet6(fd.Sysfd, p, oob, sa, 0)
+		if err == syscall.EINTR {
+			continue
+		}
+		if err == syscall.EAGAIN && fd.pd.pollable() {
+			if err = fd.pd.waitWrite(fd.isFile); err == nil {
+				continue
+			}
+		}
+		if err != nil {
+			return n, 0, err
+		}
+		return n, len(oob), err
+	}
+}
+
+// Accept wraps the accept network call.
+func (fd *FD) Accept() (int, syscall.Sockaddr, string, error) {
+	if err := fd.readLock(); err != nil {
+		return -1, nil, "", err
+	}
+	defer fd.readUnlock()
+
+	if err := fd.pd.prepareRead(fd.isFile); err != nil {
+		return -1, nil, "", err
+	}
+	for {
+		s, rsa, errcall, err := accept(fd.Sysfd)
+		if err == nil {
+			return s, rsa, "", err
+		}
+		switch err {
+		case syscall.EINTR:
+			continue
+		case syscall.EAGAIN:
+			if fd.pd.pollable() {
+				if err = fd.pd.waitRead(fd.isFile); err == nil {
+					continue
+				}
+			}
+		case syscall.ECONNABORTED:
+			// This means that a socket on the listen
+			// queue was closed before we Accept()ed it;
+			// it's a silly error, so try again.
+			continue
+		}
+		return -1, nil, errcall, err
+	}
+}
+
+// Seek wraps syscall.Seek.
+func (fd *FD) Seek(offset int64, whence int) (int64, error) {
+	if err := fd.incref(); err != nil {
+		return 0, err
+	}
+	defer fd.decref()
+	return syscall.Seek(fd.Sysfd, offset, whence)
+}
+
+// ReadDirent wraps syscall.ReadDirent.
+// We treat this like an ordinary system call rather than a call
+// that tries to fill the buffer.
+func (fd *FD) ReadDirent(buf []byte) (int, error) {
+	if err := fd.incref(); err != nil {
+		return 0, err
+	}
+	defer fd.decref()
+	for {
+		n, err := ignoringEINTRIO(syscall.ReadDirent, fd.Sysfd, buf)
+		if err != nil {
+			n = 0
+			if err == syscall.EAGAIN && fd.pd.pollable() {
+				if err = fd.pd.waitRead(fd.isFile); err == nil {
+					continue
+				}
+			}
+		}
+		// Do not call eofError; caller does not expect to see io.EOF.
+		return n, err
+	}
+}
+
+// Fchmod wraps syscall.Fchmod.
+func (fd *FD) Fchmod(mode uint32) error {
+	if err := fd.incref(); err != nil {
+		return err
+	}
+	defer fd.decref()
+	return ignoringEINTR(func() error {
+		return syscall.Fchmod(fd.Sysfd, mode)
+	})
+}
+
+// Fchdir wraps syscall.Fchdir.
+func (fd *FD) Fchdir() error {
+	if err := fd.incref(); err != nil {
+		return err
+	}
+	defer fd.decref()
+	return syscall.Fchdir(fd.Sysfd)
+}
+
+// Fstat wraps syscall.Fstat
+func (fd *FD) Fstat(s *syscall.Stat_t) error {
+	if err := fd.incref(); err != nil {
+		return err
+	}
+	defer fd.decref()
+	return ignoringEINTR(func() error {
+		return syscall.Fstat(fd.Sysfd, s)
+	})
+}
+
+// tryDupCloexec indicates whether F_DUPFD_CLOEXEC should be used.
+// If the kernel doesn't support it, this is set to 0.
+var tryDupCloexec = int32(1)
+
+// DupCloseOnExec dups fd and marks it close-on-exec.
+func DupCloseOnExec(fd int) (int, string, error) {
+	if syscall.F_DUPFD_CLOEXEC != 0 && atomic.LoadInt32(&tryDupCloexec) == 1 {
+		r0, e1 := fcntl(fd, syscall.F_DUPFD_CLOEXEC, 0)
+		if e1 == nil {
+			return r0, "", nil
+		}
+		switch e1.(syscall.Errno) {
+		case syscall.EINVAL, syscall.ENOSYS:
+			// Old kernel, or js/wasm (which returns
+			// ENOSYS). Fall back to the portable way from
+			// now on.
+			atomic.StoreInt32(&tryDupCloexec, 0)
+		default:
+			return -1, "fcntl", e1
+		}
+	}
+	return dupCloseOnExecOld(fd)
+}
+
+// dupCloseOnExecOld is the traditional way to dup an fd and
+// set its O_CLOEXEC bit, using two system calls.
+func dupCloseOnExecOld(fd int) (int, string, error) {
+	syscall.ForkLock.RLock()
+	defer syscall.ForkLock.RUnlock()
+	newfd, err := syscall.Dup(fd)
+	if err != nil {
+		return -1, "dup", err
+	}
+	syscall.CloseOnExec(newfd)
+	return newfd, "", nil
+}
+
+// Dup duplicates the file descriptor.
+func (fd *FD) Dup() (int, string, error) {
+	if err := fd.incref(); err != nil {
+		return -1, "", err
+	}
+	defer fd.decref()
+	return DupCloseOnExec(fd.Sysfd)
+}
+
+// On Unix variants only, expose the IO event for the net code.
+
+// WaitWrite waits until data can be read from fd.
+func (fd *FD) WaitWrite() error {
+	return fd.pd.waitWrite(fd.isFile)
+}
+
+// WriteOnce is for testing only. It makes a single write call.
+func (fd *FD) WriteOnce(p []byte) (int, error) {
+	if err := fd.writeLock(); err != nil {
+		return 0, err
+	}
+	defer fd.writeUnlock()
+	return ignoringEINTRIO(syscall.Write, fd.Sysfd, p)
+}
+
+// RawRead invokes the user-defined function f for a read operation.
+func (fd *FD) RawRead(f func(uintptr) bool) error {
+	if err := fd.readLock(); err != nil {
+		return err
+	}
+	defer fd.readUnlock()
+	if err := fd.pd.prepareRead(fd.isFile); err != nil {
+		return err
+	}
+	for {
+		if f(uintptr(fd.Sysfd)) {
+			return nil
+		}
+		if err := fd.pd.waitRead(fd.isFile); err != nil {
+			return err
+		}
+	}
+}
+
+// RawWrite invokes the user-defined function f for a write operation.
+func (fd *FD) RawWrite(f func(uintptr) bool) error {
+	if err := fd.writeLock(); err != nil {
+		return err
+	}
+	defer fd.writeUnlock()
+	if err := fd.pd.prepareWrite(fd.isFile); err != nil {
+		return err
+	}
+	for {
+		if f(uintptr(fd.Sysfd)) {
+			return nil
+		}
+		if err := fd.pd.waitWrite(fd.isFile); err != nil {
+			return err
+		}
+	}
+}
+
+// ignoringEINTRIO is like ignoringEINTR, but just for IO calls.
+func ignoringEINTRIO(fn func(fd int, p []byte) (int, error), fd int, p []byte) (int, error) {
+	for {
+		n, err := fn(fd, p)
+		if err != syscall.EINTR {
+			return n, err
+		}
+	}
+}
diff --git a/contrib/go/_std_1.20/src/internal/poll/fd_windows.go b/contrib/go/_std_1.20/src/internal/poll/fd_windows.go
new file mode 100644
index 0000000000..3a4a74f2ae
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/fd_windows.go
@@ -0,0 +1,1321 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package poll
+
+import (
+	"errors"
+	"internal/race"
+	"internal/syscall/windows"
+	"io"
+	"sync"
+	"syscall"
+	"unicode/utf16"
+	"unicode/utf8"
+	"unsafe"
+)
+
+var (
+	initErr error
+	ioSync  uint64
+)
+
+// This package uses the SetFileCompletionNotificationModes Windows
+// API to skip calling GetQueuedCompletionStatus if an IO operation
+// completes synchronously. There is a known bug where
+// SetFileCompletionNotificationModes crashes on some systems (see
+// https://support.microsoft.com/kb/2568167 for details).
+
+var useSetFileCompletionNotificationModes bool // determines is SetFileCompletionNotificationModes is present and safe to use
+
+// checkSetFileCompletionNotificationModes verifies that
+// SetFileCompletionNotificationModes Windows API is present
+// on the system and is safe to use.
+// See https://support.microsoft.com/kb/2568167 for details.
+func checkSetFileCompletionNotificationModes() {
+	err := syscall.LoadSetFileCompletionNotificationModes()
+	if err != nil {
+		return
+	}
+	protos := [2]int32{syscall.IPPROTO_TCP, 0}
+	var buf [32]syscall.WSAProtocolInfo
+	len := uint32(unsafe.Sizeof(buf))
+	n, err := syscall.WSAEnumProtocols(&protos[0], &buf[0], &len)
+	if err != nil {
+		return
+	}
+	for i := int32(0); i < n; i++ {
+		if buf[i].ServiceFlags1&syscall.XP1_IFS_HANDLES == 0 {
+			return
+		}
+	}
+	useSetFileCompletionNotificationModes = true
+}
+
+func init() {
+	var d syscall.WSAData
+	e := syscall.WSAStartup(uint32(0x202), &d)
+	if e != nil {
+		initErr = e
+	}
+	checkSetFileCompletionNotificationModes()
+}
+
+// operation contains superset of data necessary to perform all async IO.
+type operation struct {
+	// Used by IOCP interface, it must be first field
+	// of the struct, as our code rely on it.
+	o syscall.Overlapped
+
+	// fields used by runtime.netpoll
+	runtimeCtx uintptr
+	mode       int32
+	errno      int32
+	qty        uint32
+
+	// fields used only by net package
+	fd     *FD
+	buf    syscall.WSABuf
+	msg    windows.WSAMsg
+	sa     syscall.Sockaddr
+	rsa    *syscall.RawSockaddrAny
+	rsan   int32
+	handle syscall.Handle
+	flags  uint32
+	bufs   []syscall.WSABuf
+}
+
+func (o *operation) InitBuf(buf []byte) {
+	o.buf.Len = uint32(len(buf))
+	o.buf.Buf = nil
+	if len(buf) != 0 {
+		o.buf.Buf = &buf[0]
+	}
+}
+
+func (o *operation) InitBufs(buf *[][]byte) {
+	if o.bufs == nil {
+		o.bufs = make([]syscall.WSABuf, 0, len(*buf))
+	} else {
+		o.bufs = o.bufs[:0]
+	}
+	for _, b := range *buf {
+		if len(b) == 0 {
+			o.bufs = append(o.bufs, syscall.WSABuf{})
+			continue
+		}
+		for len(b) > maxRW {
+			o.bufs = append(o.bufs, syscall.WSABuf{Len: maxRW, Buf: &b[0]})
+			b = b[maxRW:]
+		}
+		if len(b) > 0 {
+			o.bufs = append(o.bufs, syscall.WSABuf{Len: uint32(len(b)), Buf: &b[0]})
+		}
+	}
+}
+
+// ClearBufs clears all pointers to Buffers parameter captured
+// by InitBufs, so it can be released by garbage collector.
+func (o *operation) ClearBufs() {
+	for i := range o.bufs {
+		o.bufs[i].Buf = nil
+	}
+	o.bufs = o.bufs[:0]
+}
+
+func (o *operation) InitMsg(p []byte, oob []byte) {
+	o.InitBuf(p)
+	o.msg.Buffers = &o.buf
+	o.msg.BufferCount = 1
+
+	o.msg.Name = nil
+	o.msg.Namelen = 0
+
+	o.msg.Flags = 0
+	o.msg.Control.Len = uint32(len(oob))
+	o.msg.Control.Buf = nil
+	if len(oob) != 0 {
+		o.msg.Control.Buf = &oob[0]
+	}
+}
+
+// execIO executes a single IO operation o. It submits and cancels
+// IO in the current thread for systems where Windows CancelIoEx API
+// is available. Alternatively, it passes the request onto
+// runtime netpoll and waits for completion or cancels request.
+func execIO(o *operation, submit func(o *operation) error) (int, error) {
+	if o.fd.pd.runtimeCtx == 0 {
+		return 0, errors.New("internal error: polling on unsupported descriptor type")
+	}
+
+	fd := o.fd
+	// Notify runtime netpoll about starting IO.
+	err := fd.pd.prepare(int(o.mode), fd.isFile)
+	if err != nil {
+		return 0, err
+	}
+	// Start IO.
+	err = submit(o)
+	switch err {
+	case nil:
+		// IO completed immediately
+		if o.fd.skipSyncNotif {
+			// No completion message will follow, so return immediately.
+			return int(o.qty), nil
+		}
+		// Need to get our completion message anyway.
+	case syscall.ERROR_IO_PENDING:
+		// IO started, and we have to wait for its completion.
+		err = nil
+	default:
+		return 0, err
+	}
+	// Wait for our request to complete.
+	err = fd.pd.wait(int(o.mode), fd.isFile)
+	if err == nil {
+		// All is good. Extract our IO results and return.
+		if o.errno != 0 {
+			err = syscall.Errno(o.errno)
+			// More data available. Return back the size of received data.
+			if err == syscall.ERROR_MORE_DATA || err == windows.WSAEMSGSIZE {
+				return int(o.qty), err
+			}
+			return 0, err
+		}
+		return int(o.qty), nil
+	}
+	// IO is interrupted by "close" or "timeout"
+	netpollErr := err
+	switch netpollErr {
+	case ErrNetClosing, ErrFileClosing, ErrDeadlineExceeded:
+		// will deal with those.
+	default:
+		panic("unexpected runtime.netpoll error: " + netpollErr.Error())
+	}
+	// Cancel our request.
+	err = syscall.CancelIoEx(fd.Sysfd, &o.o)
+	// Assuming ERROR_NOT_FOUND is returned, if IO is completed.
+	if err != nil && err != syscall.ERROR_NOT_FOUND {
+		// TODO(brainman): maybe do something else, but panic.
+		panic(err)
+	}
+	// Wait for cancellation to complete.
+	fd.pd.waitCanceled(int(o.mode))
+	if o.errno != 0 {
+		err = syscall.Errno(o.errno)
+		if err == syscall.ERROR_OPERATION_ABORTED { // IO Canceled
+			err = netpollErr
+		}
+		return 0, err
+	}
+	// We issued a cancellation request. But, it seems, IO operation succeeded
+	// before the cancellation request run. We need to treat the IO operation as
+	// succeeded (the bytes are actually sent/recv from network).
+	return int(o.qty), nil
+}
+
+// FD is a file descriptor. The net and os packages embed this type in
+// a larger type representing a network connection or OS file.
+type FD struct {
+	// Lock sysfd and serialize access to Read and Write methods.
+	fdmu fdMutex
+
+	// System file descriptor. Immutable until Close.
+	Sysfd syscall.Handle
+
+	// Read operation.
+	rop operation
+	// Write operation.
+	wop operation
+
+	// I/O poller.
+	pd pollDesc
+
+	// Used to implement pread/pwrite.
+	l sync.Mutex
+
+	// For console I/O.
+	lastbits       []byte   // first few bytes of the last incomplete rune in last write
+	readuint16     []uint16 // buffer to hold uint16s obtained with ReadConsole
+	readbyte       []byte   // buffer to hold decoding of readuint16 from utf16 to utf8
+	readbyteOffset int      // readbyte[readOffset:] is yet to be consumed with file.Read
+
+	// Semaphore signaled when file is closed.
+	csema uint32
+
+	skipSyncNotif bool
+
+	// Whether this is a streaming descriptor, as opposed to a
+	// packet-based descriptor like a UDP socket.
+	IsStream bool
+
+	// Whether a zero byte read indicates EOF. This is false for a
+	// message based socket connection.
+	ZeroReadIsEOF bool
+
+	// Whether this is a file rather than a network socket.
+	isFile bool
+
+	// The kind of this file.
+	kind fileKind
+}
+
+// fileKind describes the kind of file.
+type fileKind byte
+
+const (
+	kindNet fileKind = iota
+	kindFile
+	kindConsole
+	kindPipe
+)
+
+// logInitFD is set by tests to enable file descriptor initialization logging.
+var logInitFD func(net string, fd *FD, err error)
+
+// Init initializes the FD. The Sysfd field should already be set.
+// This can be called multiple times on a single FD.
+// The net argument is a network name from the net package (e.g., "tcp"),
+// or "file" or "console" or "dir".
+// Set pollable to true if fd should be managed by runtime netpoll.
+func (fd *FD) Init(net string, pollable bool) (string, error) {
+	if initErr != nil {
+		return "", initErr
+	}
+
+	switch net {
+	case "file", "dir":
+		fd.kind = kindFile
+	case "console":
+		fd.kind = kindConsole
+	case "pipe":
+		fd.kind = kindPipe
+	case "tcp", "tcp4", "tcp6",
+		"udp", "udp4", "udp6",
+		"ip", "ip4", "ip6",
+		"unix", "unixgram", "unixpacket":
+		fd.kind = kindNet
+	default:
+		return "", errors.New("internal error: unknown network type " + net)
+	}
+	fd.isFile = fd.kind != kindNet
+
+	var err error
+	if pollable {
+		// Only call init for a network socket.
+		// This means that we don't add files to the runtime poller.
+		// Adding files to the runtime poller can confuse matters
+		// if the user is doing their own overlapped I/O.
+		// See issue #21172.
+		//
+		// In general the code below avoids calling the execIO
+		// function for non-network sockets. If some method does
+		// somehow call execIO, then execIO, and therefore the
+		// calling method, will return an error, because
+		// fd.pd.runtimeCtx will be 0.
+		err = fd.pd.init(fd)
+	}
+	if logInitFD != nil {
+		logInitFD(net, fd, err)
+	}
+	if err != nil {
+		return "", err
+	}
+	if pollable && useSetFileCompletionNotificationModes {
+		// We do not use events, so we can skip them always.
+		flags := uint8(syscall.FILE_SKIP_SET_EVENT_ON_HANDLE)
+		// It's not safe to skip completion notifications for UDP:
+		// https://docs.microsoft.com/en-us/archive/blogs/winserverperformance/designing-applications-for-high-performance-part-iii
+		if net == "tcp" {
+			flags |= syscall.FILE_SKIP_COMPLETION_PORT_ON_SUCCESS
+		}
+		err := syscall.SetFileCompletionNotificationModes(fd.Sysfd, flags)
+		if err == nil && flags&syscall.FILE_SKIP_COMPLETION_PORT_ON_SUCCESS != 0 {
+			fd.skipSyncNotif = true
+		}
+	}
+	// Disable SIO_UDP_CONNRESET behavior.
+	// http://support.microsoft.com/kb/263823
+	switch net {
+	case "udp", "udp4", "udp6":
+		ret := uint32(0)
+		flag := uint32(0)
+		size := uint32(unsafe.Sizeof(flag))
+		err := syscall.WSAIoctl(fd.Sysfd, syscall.SIO_UDP_CONNRESET, (*byte)(unsafe.Pointer(&flag)), size, nil, 0, &ret, nil, 0)
+		if err != nil {
+			return "wsaioctl", err
+		}
+	}
+	fd.rop.mode = 'r'
+	fd.wop.mode = 'w'
+	fd.rop.fd = fd
+	fd.wop.fd = fd
+	fd.rop.runtimeCtx = fd.pd.runtimeCtx
+	fd.wop.runtimeCtx = fd.pd.runtimeCtx
+	return "", nil
+}
+
+func (fd *FD) destroy() error {
+	if fd.Sysfd == syscall.InvalidHandle {
+		return syscall.EINVAL
+	}
+	// Poller may want to unregister fd in readiness notification mechanism,
+	// so this must be executed before fd.CloseFunc.
+	fd.pd.close()
+	var err error
+	switch fd.kind {
+	case kindNet:
+		// The net package uses the CloseFunc variable for testing.
+		err = CloseFunc(fd.Sysfd)
+	default:
+		err = syscall.CloseHandle(fd.Sysfd)
+	}
+	fd.Sysfd = syscall.InvalidHandle
+	runtime_Semrelease(&fd.csema)
+	return err
+}
+
+// Close closes the FD. The underlying file descriptor is closed by
+// the destroy method when there are no remaining references.
+func (fd *FD) Close() error {
+	if !fd.fdmu.increfAndClose() {
+		return errClosing(fd.isFile)
+	}
+	if fd.kind == kindPipe {
+		syscall.CancelIoEx(fd.Sysfd, nil)
+	}
+	// unblock pending reader and writer
+	fd.pd.evict()
+	err := fd.decref()
+	// Wait until the descriptor is closed. If this was the only
+	// reference, it is already closed.
+	runtime_Semacquire(&fd.csema)
+	return err
+}
+
+// Windows ReadFile and WSARecv use DWORD (uint32) parameter to pass buffer length.
+// This prevents us reading blocks larger than 4GB.
+// See golang.org/issue/26923.
+const maxRW = 1 << 30 // 1GB is large enough and keeps subsequent reads aligned
+
+// Read implements io.Reader.
+func (fd *FD) Read(buf []byte) (int, error) {
+	if err := fd.readLock(); err != nil {
+		return 0, err
+	}
+	defer fd.readUnlock()
+
+	if len(buf) > maxRW {
+		buf = buf[:maxRW]
+	}
+
+	var n int
+	var err error
+	if fd.isFile {
+		fd.l.Lock()
+		defer fd.l.Unlock()
+		switch fd.kind {
+		case kindConsole:
+			n, err = fd.readConsole(buf)
+		default:
+			n, err = syscall.Read(fd.Sysfd, buf)
+			if fd.kind == kindPipe && err == syscall.ERROR_OPERATION_ABORTED {
+				// Close uses CancelIoEx to interrupt concurrent I/O for pipes.
+				// If the fd is a pipe and the Read was interrupted by CancelIoEx,
+				// we assume it is interrupted by Close.
+				err = ErrFileClosing
+			}
+		}
+		if err != nil {
+			n = 0
+		}
+	} else {
+		o := &fd.rop
+		o.InitBuf(buf)
+		n, err = execIO(o, func(o *operation) error {
+			return syscall.WSARecv(o.fd.Sysfd, &o.buf, 1, &o.qty, &o.flags, &o.o, nil)
+		})
+		if race.Enabled {
+			race.Acquire(unsafe.Pointer(&ioSync))
+		}
+	}
+	if len(buf) != 0 {
+		err = fd.eofError(n, err)
+	}
+	return n, err
+}
+
+var ReadConsole = syscall.ReadConsole // changed for testing
+
+// readConsole reads utf16 characters from console File,
+// encodes them into utf8 and stores them in buffer b.
+// It returns the number of utf8 bytes read and an error, if any.
+func (fd *FD) readConsole(b []byte) (int, error) {
+	if len(b) == 0 {
+		return 0, nil
+	}
+
+	if fd.readuint16 == nil {
+		// Note: syscall.ReadConsole fails for very large buffers.
+		// The limit is somewhere around (but not exactly) 16384.
+		// Stay well below.
+		fd.readuint16 = make([]uint16, 0, 10000)
+		fd.readbyte = make([]byte, 0, 4*cap(fd.readuint16))
+	}
+
+	for fd.readbyteOffset >= len(fd.readbyte) {
+		n := cap(fd.readuint16) - len(fd.readuint16)
+		if n > len(b) {
+			n = len(b)
+		}
+		var nw uint32
+		err := ReadConsole(fd.Sysfd, &fd.readuint16[:len(fd.readuint16)+1][len(fd.readuint16)], uint32(n), &nw, nil)
+		if err != nil {
+			return 0, err
+		}
+		uint16s := fd.readuint16[:len(fd.readuint16)+int(nw)]
+		fd.readuint16 = fd.readuint16[:0]
+		buf := fd.readbyte[:0]
+		for i := 0; i < len(uint16s); i++ {
+			r := rune(uint16s[i])
+			if utf16.IsSurrogate(r) {
+				if i+1 == len(uint16s) {
+					if nw > 0 {
+						// Save half surrogate pair for next time.
+						fd.readuint16 = fd.readuint16[:1]
+						fd.readuint16[0] = uint16(r)
+						break
+					}
+					r = utf8.RuneError
+				} else {
+					r = utf16.DecodeRune(r, rune(uint16s[i+1]))
+					if r != utf8.RuneError {
+						i++
+					}
+				}
+			}
+			buf = utf8.AppendRune(buf, r)
+		}
+		fd.readbyte = buf
+		fd.readbyteOffset = 0
+		if nw == 0 {
+			break
+		}
+	}
+
+	src := fd.readbyte[fd.readbyteOffset:]
+	var i int
+	for i = 0; i < len(src) && i < len(b); i++ {
+		x := src[i]
+		if x == 0x1A { // Ctrl-Z
+			if i == 0 {
+				fd.readbyteOffset++
+			}
+			break
+		}
+		b[i] = x
+	}
+	fd.readbyteOffset += i
+	return i, nil
+}
+
+// Pread emulates the Unix pread system call.
+func (fd *FD) Pread(b []byte, off int64) (int, error) {
+	// Call incref, not readLock, because since pread specifies the
+	// offset it is independent from other reads.
+	if err := fd.incref(); err != nil {
+		return 0, err
+	}
+	defer fd.decref()
+
+	if len(b) > maxRW {
+		b = b[:maxRW]
+	}
+
+	fd.l.Lock()
+	defer fd.l.Unlock()
+	curoffset, e := syscall.Seek(fd.Sysfd, 0, io.SeekCurrent)
+	if e != nil {
+		return 0, e
+	}
+	defer syscall.Seek(fd.Sysfd, curoffset, io.SeekStart)
+	o := syscall.Overlapped{
+		OffsetHigh: uint32(off >> 32),
+		Offset:     uint32(off),
+	}
+	var done uint32
+	e = syscall.ReadFile(fd.Sysfd, b, &done, &o)
+	if e != nil {
+		done = 0
+		if e == syscall.ERROR_HANDLE_EOF {
+			e = io.EOF
+		}
+	}
+	if len(b) != 0 {
+		e = fd.eofError(int(done), e)
+	}
+	return int(done), e
+}
+
+// ReadFrom wraps the recvfrom network call.
+func (fd *FD) ReadFrom(buf []byte) (int, syscall.Sockaddr, error) {
+	if len(buf) == 0 {
+		return 0, nil, nil
+	}
+	if len(buf) > maxRW {
+		buf = buf[:maxRW]
+	}
+	if err := fd.readLock(); err != nil {
+		return 0, nil, err
+	}
+	defer fd.readUnlock()
+	o := &fd.rop
+	o.InitBuf(buf)
+	n, err := execIO(o, func(o *operation) error {
+		if o.rsa == nil {
+			o.rsa = new(syscall.RawSockaddrAny)
+		}
+		o.rsan = int32(unsafe.Sizeof(*o.rsa))
+		return syscall.WSARecvFrom(o.fd.Sysfd, &o.buf, 1, &o.qty, &o.flags, o.rsa, &o.rsan, &o.o, nil)
+	})
+	err = fd.eofError(n, err)
+	if err != nil {
+		return n, nil, err
+	}
+	sa, _ := o.rsa.Sockaddr()
+	return n, sa, nil
+}
+
+// ReadFromInet4 wraps the recvfrom network call for IPv4.
+func (fd *FD) ReadFromInet4(buf []byte, sa4 *syscall.SockaddrInet4) (int, error) {
+	if len(buf) == 0 {
+		return 0, nil
+	}
+	if len(buf) > maxRW {
+		buf = buf[:maxRW]
+	}
+	if err := fd.readLock(); err != nil {
+		return 0, err
+	}
+	defer fd.readUnlock()
+	o := &fd.rop
+	o.InitBuf(buf)
+	n, err := execIO(o, func(o *operation) error {
+		if o.rsa == nil {
+			o.rsa = new(syscall.RawSockaddrAny)
+		}
+		o.rsan = int32(unsafe.Sizeof(*o.rsa))
+		return syscall.WSARecvFrom(o.fd.Sysfd, &o.buf, 1, &o.qty, &o.flags, o.rsa, &o.rsan, &o.o, nil)
+	})
+	err = fd.eofError(n, err)
+	if err != nil {
+		return n, err
+	}
+	rawToSockaddrInet4(o.rsa, sa4)
+	return n, err
+}
+
+// ReadFromInet6 wraps the recvfrom network call for IPv6.
+func (fd *FD) ReadFromInet6(buf []byte, sa6 *syscall.SockaddrInet6) (int, error) {
+	if len(buf) == 0 {
+		return 0, nil
+	}
+	if len(buf) > maxRW {
+		buf = buf[:maxRW]
+	}
+	if err := fd.readLock(); err != nil {
+		return 0, err
+	}
+	defer fd.readUnlock()
+	o := &fd.rop
+	o.InitBuf(buf)
+	n, err := execIO(o, func(o *operation) error {
+		if o.rsa == nil {
+			o.rsa = new(syscall.RawSockaddrAny)
+		}
+		o.rsan = int32(unsafe.Sizeof(*o.rsa))
+		return syscall.WSARecvFrom(o.fd.Sysfd, &o.buf, 1, &o.qty, &o.flags, o.rsa, &o.rsan, &o.o, nil)
+	})
+	err = fd.eofError(n, err)
+	if err != nil {
+		return n, err
+	}
+	rawToSockaddrInet6(o.rsa, sa6)
+	return n, err
+}
+
+// Write implements io.Writer.
+func (fd *FD) Write(buf []byte) (int, error) {
+	if err := fd.writeLock(); err != nil {
+		return 0, err
+	}
+	defer fd.writeUnlock()
+	if fd.isFile {
+		fd.l.Lock()
+		defer fd.l.Unlock()
+	}
+
+	ntotal := 0
+	for len(buf) > 0 {
+		b := buf
+		if len(b) > maxRW {
+			b = b[:maxRW]
+		}
+		var n int
+		var err error
+		if fd.isFile {
+			switch fd.kind {
+			case kindConsole:
+				n, err = fd.writeConsole(b)
+			default:
+				n, err = syscall.Write(fd.Sysfd, b)
+				if fd.kind == kindPipe && err == syscall.ERROR_OPERATION_ABORTED {
+					// Close uses CancelIoEx to interrupt concurrent I/O for pipes.
+					// If the fd is a pipe and the Write was interrupted by CancelIoEx,
+					// we assume it is interrupted by Close.
+					err = ErrFileClosing
+				}
+			}
+			if err != nil {
+				n = 0
+			}
+		} else {
+			if race.Enabled {
+				race.ReleaseMerge(unsafe.Pointer(&ioSync))
+			}
+			o := &fd.wop
+			o.InitBuf(b)
+			n, err = execIO(o, func(o *operation) error {
+				return syscall.WSASend(o.fd.Sysfd, &o.buf, 1, &o.qty, 0, &o.o, nil)
+			})
+		}
+		ntotal += n
+		if err != nil {
+			return ntotal, err
+		}
+		buf = buf[n:]
+	}
+	return ntotal, nil
+}
+
+// writeConsole writes len(b) bytes to the console File.
+// It returns the number of bytes written and an error, if any.
+func (fd *FD) writeConsole(b []byte) (int, error) {
+	n := len(b)
+	runes := make([]rune, 0, 256)
+	if len(fd.lastbits) > 0 {
+		b = append(fd.lastbits, b...)
+		fd.lastbits = nil
+
+	}
+	for len(b) >= utf8.UTFMax || utf8.FullRune(b) {
+		r, l := utf8.DecodeRune(b)
+		runes = append(runes, r)
+		b = b[l:]
+	}
+	if len(b) > 0 {
+		fd.lastbits = make([]byte, len(b))
+		copy(fd.lastbits, b)
+	}
+	// syscall.WriteConsole seems to fail, if given large buffer.
+	// So limit the buffer to 16000 characters. This number was
+	// discovered by experimenting with syscall.WriteConsole.
+	const maxWrite = 16000
+	for len(runes) > 0 {
+		m := len(runes)
+		if m > maxWrite {
+			m = maxWrite
+		}
+		chunk := runes[:m]
+		runes = runes[m:]
+		uint16s := utf16.Encode(chunk)
+		for len(uint16s) > 0 {
+			var written uint32
+			err := syscall.WriteConsole(fd.Sysfd, &uint16s[0], uint32(len(uint16s)), &written, nil)
+			if err != nil {
+				return 0, err
+			}
+			uint16s = uint16s[written:]
+		}
+	}
+	return n, nil
+}
+
+// Pwrite emulates the Unix pwrite system call.
+func (fd *FD) Pwrite(buf []byte, off int64) (int, error) {
+	// Call incref, not writeLock, because since pwrite specifies the
+	// offset it is independent from other writes.
+	if err := fd.incref(); err != nil {
+		return 0, err
+	}
+	defer fd.decref()
+
+	fd.l.Lock()
+	defer fd.l.Unlock()
+	curoffset, e := syscall.Seek(fd.Sysfd, 0, io.SeekCurrent)
+	if e != nil {
+		return 0, e
+	}
+	defer syscall.Seek(fd.Sysfd, curoffset, io.SeekStart)
+
+	ntotal := 0
+	for len(buf) > 0 {
+		b := buf
+		if len(b) > maxRW {
+			b = b[:maxRW]
+		}
+		var n uint32
+		o := syscall.Overlapped{
+			OffsetHigh: uint32(off >> 32),
+			Offset:     uint32(off),
+		}
+		e = syscall.WriteFile(fd.Sysfd, b, &n, &o)
+		ntotal += int(n)
+		if e != nil {
+			return ntotal, e
+		}
+		buf = buf[n:]
+		off += int64(n)
+	}
+	return ntotal, nil
+}
+
+// Writev emulates the Unix writev system call.
+func (fd *FD) Writev(buf *[][]byte) (int64, error) {
+	if len(*buf) == 0 {
+		return 0, nil
+	}
+	if err := fd.writeLock(); err != nil {
+		return 0, err
+	}
+	defer fd.writeUnlock()
+	if race.Enabled {
+		race.ReleaseMerge(unsafe.Pointer(&ioSync))
+	}
+	o := &fd.wop
+	o.InitBufs(buf)
+	n, err := execIO(o, func(o *operation) error {
+		return syscall.WSASend(o.fd.Sysfd, &o.bufs[0], uint32(len(o.bufs)), &o.qty, 0, &o.o, nil)
+	})
+	o.ClearBufs()
+	TestHookDidWritev(n)
+	consume(buf, int64(n))
+	return int64(n), err
+}
+
+// WriteTo wraps the sendto network call.
+func (fd *FD) WriteTo(buf []byte, sa syscall.Sockaddr) (int, error) {
+	if err := fd.writeLock(); err != nil {
+		return 0, err
+	}
+	defer fd.writeUnlock()
+
+	if len(buf) == 0 {
+		// handle zero-byte payload
+		o := &fd.wop
+		o.InitBuf(buf)
+		o.sa = sa
+		n, err := execIO(o, func(o *operation) error {
+			return syscall.WSASendto(o.fd.Sysfd, &o.buf, 1, &o.qty, 0, o.sa, &o.o, nil)
+		})
+		return n, err
+	}
+
+	ntotal := 0
+	for len(buf) > 0 {
+		b := buf
+		if len(b) > maxRW {
+			b = b[:maxRW]
+		}
+		o := &fd.wop
+		o.InitBuf(b)
+		o.sa = sa
+		n, err := execIO(o, func(o *operation) error {
+			return syscall.WSASendto(o.fd.Sysfd, &o.buf, 1, &o.qty, 0, o.sa, &o.o, nil)
+		})
+		ntotal += int(n)
+		if err != nil {
+			return ntotal, err
+		}
+		buf = buf[n:]
+	}
+	return ntotal, nil
+}
+
+// WriteToInet4 is WriteTo, specialized for syscall.SockaddrInet4.
+func (fd *FD) WriteToInet4(buf []byte, sa4 *syscall.SockaddrInet4) (int, error) {
+	if err := fd.writeLock(); err != nil {
+		return 0, err
+	}
+	defer fd.writeUnlock()
+
+	if len(buf) == 0 {
+		// handle zero-byte payload
+		o := &fd.wop
+		o.InitBuf(buf)
+		n, err := execIO(o, func(o *operation) error {
+			return windows.WSASendtoInet4(o.fd.Sysfd, &o.buf, 1, &o.qty, 0, sa4, &o.o, nil)
+		})
+		return n, err
+	}
+
+	ntotal := 0
+	for len(buf) > 0 {
+		b := buf
+		if len(b) > maxRW {
+			b = b[:maxRW]
+		}
+		o := &fd.wop
+		o.InitBuf(b)
+		n, err := execIO(o, func(o *operation) error {
+			return windows.WSASendtoInet4(o.fd.Sysfd, &o.buf, 1, &o.qty, 0, sa4, &o.o, nil)
+		})
+		ntotal += int(n)
+		if err != nil {
+			return ntotal, err
+		}
+		buf = buf[n:]
+	}
+	return ntotal, nil
+}
+
+// WriteToInet6 is WriteTo, specialized for syscall.SockaddrInet6.
+func (fd *FD) WriteToInet6(buf []byte, sa6 *syscall.SockaddrInet6) (int, error) {
+	if err := fd.writeLock(); err != nil {
+		return 0, err
+	}
+	defer fd.writeUnlock()
+
+	if len(buf) == 0 {
+		// handle zero-byte payload
+		o := &fd.wop
+		o.InitBuf(buf)
+		n, err := execIO(o, func(o *operation) error {
+			return windows.WSASendtoInet6(o.fd.Sysfd, &o.buf, 1, &o.qty, 0, sa6, &o.o, nil)
+		})
+		return n, err
+	}
+
+	ntotal := 0
+	for len(buf) > 0 {
+		b := buf
+		if len(b) > maxRW {
+			b = b[:maxRW]
+		}
+		o := &fd.wop
+		o.InitBuf(b)
+		n, err := execIO(o, func(o *operation) error {
+			return windows.WSASendtoInet6(o.fd.Sysfd, &o.buf, 1, &o.qty, 0, sa6, &o.o, nil)
+		})
+		ntotal += int(n)
+		if err != nil {
+			return ntotal, err
+		}
+		buf = buf[n:]
+	}
+	return ntotal, nil
+}
+
+// Call ConnectEx. This doesn't need any locking, since it is only
+// called when the descriptor is first created. This is here rather
+// than in the net package so that it can use fd.wop.
+func (fd *FD) ConnectEx(ra syscall.Sockaddr) error {
+	o := &fd.wop
+	o.sa = ra
+	_, err := execIO(o, func(o *operation) error {
+		return ConnectExFunc(o.fd.Sysfd, o.sa, nil, 0, nil, &o.o)
+	})
+	return err
+}
+
+func (fd *FD) acceptOne(s syscall.Handle, rawsa []syscall.RawSockaddrAny, o *operation) (string, error) {
+	// Submit accept request.
+	o.handle = s
+	o.rsan = int32(unsafe.Sizeof(rawsa[0]))
+	_, err := execIO(o, func(o *operation) error {
+		return AcceptFunc(o.fd.Sysfd, o.handle, (*byte)(unsafe.Pointer(&rawsa[0])), 0, uint32(o.rsan), uint32(o.rsan), &o.qty, &o.o)
+	})
+	if err != nil {
+		CloseFunc(s)
+		return "acceptex", err
+	}
+
+	// Inherit properties of the listening socket.
+	err = syscall.Setsockopt(s, syscall.SOL_SOCKET, syscall.SO_UPDATE_ACCEPT_CONTEXT, (*byte)(unsafe.Pointer(&fd.Sysfd)), int32(unsafe.Sizeof(fd.Sysfd)))
+	if err != nil {
+		CloseFunc(s)
+		return "setsockopt", err
+	}
+
+	return "", nil
+}
+
+// Accept handles accepting a socket. The sysSocket parameter is used
+// to allocate the net socket.
+func (fd *FD) Accept(sysSocket func() (syscall.Handle, error)) (syscall.Handle, []syscall.RawSockaddrAny, uint32, string, error) {
+	if err := fd.readLock(); err != nil {
+		return syscall.InvalidHandle, nil, 0, "", err
+	}
+	defer fd.readUnlock()
+
+	o := &fd.rop
+	var rawsa [2]syscall.RawSockaddrAny
+	for {
+		s, err := sysSocket()
+		if err != nil {
+			return syscall.InvalidHandle, nil, 0, "", err
+		}
+
+		errcall, err := fd.acceptOne(s, rawsa[:], o)
+		if err == nil {
+			return s, rawsa[:], uint32(o.rsan), "", nil
+		}
+
+		// Sometimes we see WSAECONNRESET and ERROR_NETNAME_DELETED is
+		// returned here. These happen if connection reset is received
+		// before AcceptEx could complete. These errors relate to new
+		// connection, not to AcceptEx, so ignore broken connection and
+		// try AcceptEx again for more connections.
+		errno, ok := err.(syscall.Errno)
+		if !ok {
+			return syscall.InvalidHandle, nil, 0, errcall, err
+		}
+		switch errno {
+		case syscall.ERROR_NETNAME_DELETED, syscall.WSAECONNRESET:
+			// ignore these and try again
+		default:
+			return syscall.InvalidHandle, nil, 0, errcall, err
+		}
+	}
+}
+
+// Seek wraps syscall.Seek.
+func (fd *FD) Seek(offset int64, whence int) (int64, error) {
+	if err := fd.incref(); err != nil {
+		return 0, err
+	}
+	defer fd.decref()
+
+	fd.l.Lock()
+	defer fd.l.Unlock()
+
+	return syscall.Seek(fd.Sysfd, offset, whence)
+}
+
+// Fchmod updates syscall.ByHandleFileInformation.Fileattributes when needed.
+func (fd *FD) Fchmod(mode uint32) error {
+	if err := fd.incref(); err != nil {
+		return err
+	}
+	defer fd.decref()
+
+	var d syscall.ByHandleFileInformation
+	if err := syscall.GetFileInformationByHandle(fd.Sysfd, &d); err != nil {
+		return err
+	}
+	attrs := d.FileAttributes
+	if mode&syscall.S_IWRITE != 0 {
+		attrs &^= syscall.FILE_ATTRIBUTE_READONLY
+	} else {
+		attrs |= syscall.FILE_ATTRIBUTE_READONLY
+	}
+	if attrs == d.FileAttributes {
+		return nil
+	}
+
+	var du windows.FILE_BASIC_INFO
+	du.FileAttributes = attrs
+	l := uint32(unsafe.Sizeof(d))
+	return windows.SetFileInformationByHandle(fd.Sysfd, windows.FileBasicInfo, uintptr(unsafe.Pointer(&du)), l)
+}
+
+// Fchdir wraps syscall.Fchdir.
+func (fd *FD) Fchdir() error {
+	if err := fd.incref(); err != nil {
+		return err
+	}
+	defer fd.decref()
+	return syscall.Fchdir(fd.Sysfd)
+}
+
+// GetFileType wraps syscall.GetFileType.
+func (fd *FD) GetFileType() (uint32, error) {
+	if err := fd.incref(); err != nil {
+		return 0, err
+	}
+	defer fd.decref()
+	return syscall.GetFileType(fd.Sysfd)
+}
+
+// GetFileInformationByHandle wraps GetFileInformationByHandle.
+func (fd *FD) GetFileInformationByHandle(data *syscall.ByHandleFileInformation) error {
+	if err := fd.incref(); err != nil {
+		return err
+	}
+	defer fd.decref()
+	return syscall.GetFileInformationByHandle(fd.Sysfd, data)
+}
+
+// RawRead invokes the user-defined function f for a read operation.
+func (fd *FD) RawRead(f func(uintptr) bool) error {
+	if err := fd.readLock(); err != nil {
+		return err
+	}
+	defer fd.readUnlock()
+	for {
+		if f(uintptr(fd.Sysfd)) {
+			return nil
+		}
+
+		// Use a zero-byte read as a way to get notified when this
+		// socket is readable. h/t https://stackoverflow.com/a/42019668/332798
+		o := &fd.rop
+		o.InitBuf(nil)
+		if !fd.IsStream {
+			o.flags |= windows.MSG_PEEK
+		}
+		_, err := execIO(o, func(o *operation) error {
+			return syscall.WSARecv(o.fd.Sysfd, &o.buf, 1, &o.qty, &o.flags, &o.o, nil)
+		})
+		if err == windows.WSAEMSGSIZE {
+			// expected with a 0-byte peek, ignore.
+		} else if err != nil {
+			return err
+		}
+	}
+}
+
+// RawWrite invokes the user-defined function f for a write operation.
+func (fd *FD) RawWrite(f func(uintptr) bool) error {
+	if err := fd.writeLock(); err != nil {
+		return err
+	}
+	defer fd.writeUnlock()
+
+	if f(uintptr(fd.Sysfd)) {
+		return nil
+	}
+
+	// TODO(tmm1): find a way to detect socket writability
+	return syscall.EWINDOWS
+}
+
+func sockaddrInet4ToRaw(rsa *syscall.RawSockaddrAny, sa *syscall.SockaddrInet4) int32 {
+	*rsa = syscall.RawSockaddrAny{}
+	raw := (*syscall.RawSockaddrInet4)(unsafe.Pointer(rsa))
+	raw.Family = syscall.AF_INET
+	p := (*[2]byte)(unsafe.Pointer(&raw.Port))
+	p[0] = byte(sa.Port >> 8)
+	p[1] = byte(sa.Port)
+	raw.Addr = sa.Addr
+	return int32(unsafe.Sizeof(*raw))
+}
+
+func sockaddrInet6ToRaw(rsa *syscall.RawSockaddrAny, sa *syscall.SockaddrInet6) int32 {
+	*rsa = syscall.RawSockaddrAny{}
+	raw := (*syscall.RawSockaddrInet6)(unsafe.Pointer(rsa))
+	raw.Family = syscall.AF_INET6
+	p := (*[2]byte)(unsafe.Pointer(&raw.Port))
+	p[0] = byte(sa.Port >> 8)
+	p[1] = byte(sa.Port)
+	raw.Scope_id = sa.ZoneId
+	raw.Addr = sa.Addr
+	return int32(unsafe.Sizeof(*raw))
+}
+
+func rawToSockaddrInet4(rsa *syscall.RawSockaddrAny, sa *syscall.SockaddrInet4) {
+	pp := (*syscall.RawSockaddrInet4)(unsafe.Pointer(rsa))
+	p := (*[2]byte)(unsafe.Pointer(&pp.Port))
+	sa.Port = int(p[0])<<8 + int(p[1])
+	sa.Addr = pp.Addr
+}
+
+func rawToSockaddrInet6(rsa *syscall.RawSockaddrAny, sa *syscall.SockaddrInet6) {
+	pp := (*syscall.RawSockaddrInet6)(unsafe.Pointer(rsa))
+	p := (*[2]byte)(unsafe.Pointer(&pp.Port))
+	sa.Port = int(p[0])<<8 + int(p[1])
+	sa.ZoneId = pp.Scope_id
+	sa.Addr = pp.Addr
+}
+
+func sockaddrToRaw(rsa *syscall.RawSockaddrAny, sa syscall.Sockaddr) (int32, error) {
+	switch sa := sa.(type) {
+	case *syscall.SockaddrInet4:
+		sz := sockaddrInet4ToRaw(rsa, sa)
+		return sz, nil
+	case *syscall.SockaddrInet6:
+		sz := sockaddrInet6ToRaw(rsa, sa)
+		return sz, nil
+	default:
+		return 0, syscall.EWINDOWS
+	}
+}
+
+// ReadMsg wraps the WSARecvMsg network call.
+func (fd *FD) ReadMsg(p []byte, oob []byte, flags int) (int, int, int, syscall.Sockaddr, error) {
+	if err := fd.readLock(); err != nil {
+		return 0, 0, 0, nil, err
+	}
+	defer fd.readUnlock()
+
+	if len(p) > maxRW {
+		p = p[:maxRW]
+	}
+
+	o := &fd.rop
+	o.InitMsg(p, oob)
+	if o.rsa == nil {
+		o.rsa = new(syscall.RawSockaddrAny)
+	}
+	o.msg.Name = (syscall.Pointer)(unsafe.Pointer(o.rsa))
+	o.msg.Namelen = int32(unsafe.Sizeof(*o.rsa))
+	o.msg.Flags = uint32(flags)
+	n, err := execIO(o, func(o *operation) error {
+		return windows.WSARecvMsg(o.fd.Sysfd, &o.msg, &o.qty, &o.o, nil)
+	})
+	err = fd.eofError(n, err)
+	var sa syscall.Sockaddr
+	if err == nil {
+		sa, err = o.rsa.Sockaddr()
+	}
+	return n, int(o.msg.Control.Len), int(o.msg.Flags), sa, err
+}
+
+// ReadMsgInet4 is ReadMsg, but specialized to return a syscall.SockaddrInet4.
+func (fd *FD) ReadMsgInet4(p []byte, oob []byte, flags int, sa4 *syscall.SockaddrInet4) (int, int, int, error) {
+	if err := fd.readLock(); err != nil {
+		return 0, 0, 0, err
+	}
+	defer fd.readUnlock()
+
+	if len(p) > maxRW {
+		p = p[:maxRW]
+	}
+
+	o := &fd.rop
+	o.InitMsg(p, oob)
+	if o.rsa == nil {
+		o.rsa = new(syscall.RawSockaddrAny)
+	}
+	o.msg.Name = (syscall.Pointer)(unsafe.Pointer(o.rsa))
+	o.msg.Namelen = int32(unsafe.Sizeof(*o.rsa))
+	o.msg.Flags = uint32(flags)
+	n, err := execIO(o, func(o *operation) error {
+		return windows.WSARecvMsg(o.fd.Sysfd, &o.msg, &o.qty, &o.o, nil)
+	})
+	err = fd.eofError(n, err)
+	if err == nil {
+		rawToSockaddrInet4(o.rsa, sa4)
+	}
+	return n, int(o.msg.Control.Len), int(o.msg.Flags), err
+}
+
+// ReadMsgInet6 is ReadMsg, but specialized to return a syscall.SockaddrInet6.
+func (fd *FD) ReadMsgInet6(p []byte, oob []byte, flags int, sa6 *syscall.SockaddrInet6) (int, int, int, error) {
+	if err := fd.readLock(); err != nil {
+		return 0, 0, 0, err
+	}
+	defer fd.readUnlock()
+
+	if len(p) > maxRW {
+		p = p[:maxRW]
+	}
+
+	o := &fd.rop
+	o.InitMsg(p, oob)
+	if o.rsa == nil {
+		o.rsa = new(syscall.RawSockaddrAny)
+	}
+	o.msg.Name = (syscall.Pointer)(unsafe.Pointer(o.rsa))
+	o.msg.Namelen = int32(unsafe.Sizeof(*o.rsa))
+	o.msg.Flags = uint32(flags)
+	n, err := execIO(o, func(o *operation) error {
+		return windows.WSARecvMsg(o.fd.Sysfd, &o.msg, &o.qty, &o.o, nil)
+	})
+	err = fd.eofError(n, err)
+	if err == nil {
+		rawToSockaddrInet6(o.rsa, sa6)
+	}
+	return n, int(o.msg.Control.Len), int(o.msg.Flags), err
+}
+
+// WriteMsg wraps the WSASendMsg network call.
+func (fd *FD) WriteMsg(p []byte, oob []byte, sa syscall.Sockaddr) (int, int, error) {
+	if len(p) > maxRW {
+		return 0, 0, errors.New("packet is too large (only 1GB is allowed)")
+	}
+
+	if err := fd.writeLock(); err != nil {
+		return 0, 0, err
+	}
+	defer fd.writeUnlock()
+
+	o := &fd.wop
+	o.InitMsg(p, oob)
+	if sa != nil {
+		if o.rsa == nil {
+			o.rsa = new(syscall.RawSockaddrAny)
+		}
+		len, err := sockaddrToRaw(o.rsa, sa)
+		if err != nil {
+			return 0, 0, err
+		}
+		o.msg.Name = (syscall.Pointer)(unsafe.Pointer(o.rsa))
+		o.msg.Namelen = len
+	}
+	n, err := execIO(o, func(o *operation) error {
+		return windows.WSASendMsg(o.fd.Sysfd, &o.msg, 0, &o.qty, &o.o, nil)
+	})
+	return n, int(o.msg.Control.Len), err
+}
+
+// WriteMsgInet4 is WriteMsg specialized for syscall.SockaddrInet4.
+func (fd *FD) WriteMsgInet4(p []byte, oob []byte, sa *syscall.SockaddrInet4) (int, int, error) {
+	if len(p) > maxRW {
+		return 0, 0, errors.New("packet is too large (only 1GB is allowed)")
+	}
+
+	if err := fd.writeLock(); err != nil {
+		return 0, 0, err
+	}
+	defer fd.writeUnlock()
+
+	o := &fd.wop
+	o.InitMsg(p, oob)
+	if o.rsa == nil {
+		o.rsa = new(syscall.RawSockaddrAny)
+	}
+	len := sockaddrInet4ToRaw(o.rsa, sa)
+	o.msg.Name = (syscall.Pointer)(unsafe.Pointer(o.rsa))
+	o.msg.Namelen = len
+	n, err := execIO(o, func(o *operation) error {
+		return windows.WSASendMsg(o.fd.Sysfd, &o.msg, 0, &o.qty, &o.o, nil)
+	})
+	return n, int(o.msg.Control.Len), err
+}
+
+// WriteMsgInet6 is WriteMsg specialized for syscall.SockaddrInet6.
+func (fd *FD) WriteMsgInet6(p []byte, oob []byte, sa *syscall.SockaddrInet6) (int, int, error) {
+	if len(p) > maxRW {
+		return 0, 0, errors.New("packet is too large (only 1GB is allowed)")
+	}
+
+	if err := fd.writeLock(); err != nil {
+		return 0, 0, err
+	}
+	defer fd.writeUnlock()
+
+	o := &fd.wop
+	o.InitMsg(p, oob)
+	if o.rsa == nil {
+		o.rsa = new(syscall.RawSockaddrAny)
+	}
+	len := sockaddrInet6ToRaw(o.rsa, sa)
+	o.msg.Name = (syscall.Pointer)(unsafe.Pointer(o.rsa))
+	o.msg.Namelen = len
+	n, err := execIO(o, func(o *operation) error {
+		return windows.WSASendMsg(o.fd.Sysfd, &o.msg, 0, &o.qty, &o.o, nil)
+	})
+	return n, int(o.msg.Control.Len), err
+}
diff --git a/contrib/go/_std_1.20/src/internal/poll/fd_writev_libc.go b/contrib/go/_std_1.20/src/internal/poll/fd_writev_libc.go
new file mode 100644
index 0000000000..1b35bd9052
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/fd_writev_libc.go
@@ -0,0 +1,16 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build aix || darwin || (openbsd && !mips64) || solaris
+
+package poll
+
+import (
+	"syscall"
+	_ "unsafe" // for go:linkname
+
+)
+
+//go:linkname writev syscall.writev
+func writev(fd int, iovecs []syscall.Iovec) (uintptr, error)
diff --git a/contrib/go/_std_1.20/src/internal/poll/fd_writev_unix.go b/contrib/go/_std_1.20/src/internal/poll/fd_writev_unix.go
new file mode 100644
index 0000000000..005638b06f
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/fd_writev_unix.go
@@ -0,0 +1,29 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build dragonfly || freebsd || linux || netbsd || (openbsd && mips64)
+
+package poll
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+func writev(fd int, iovecs []syscall.Iovec) (uintptr, error) {
+	var (
+		r uintptr
+		e syscall.Errno
+	)
+	for {
+		r, _, e = syscall.Syscall(syscall.SYS_WRITEV, uintptr(fd), uintptr(unsafe.Pointer(&iovecs[0])), uintptr(len(iovecs)))
+		if e != syscall.EINTR {
+			break
+		}
+	}
+	if e != 0 {
+		return r, e
+	}
+	return r, nil
+}
diff --git a/contrib/go/_std_1.20/src/internal/poll/hook_cloexec.go b/contrib/go/_std_1.20/src/internal/poll/hook_cloexec.go
new file mode 100644
index 0000000000..5b3cdcec28
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/hook_cloexec.go
@@ -0,0 +1,12 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build dragonfly || freebsd || linux || netbsd || openbsd || solaris
+
+package poll
+
+import "syscall"
+
+// Accept4Func is used to hook the accept4 call.
+var Accept4Func func(int, int) (int, syscall.Sockaddr, error) = syscall.Accept4
diff --git a/contrib/go/_std_1.20/src/internal/poll/hook_unix.go b/contrib/go/_std_1.20/src/internal/poll/hook_unix.go
new file mode 100644
index 0000000000..1a5035675d
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/hook_unix.go
@@ -0,0 +1,15 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build unix || (js && wasm)
+
+package poll
+
+import "syscall"
+
+// CloseFunc is used to hook the close call.
+var CloseFunc func(int) error = syscall.Close
+
+// AcceptFunc is used to hook the accept call.
+var AcceptFunc func(int) (int, syscall.Sockaddr, error) = syscall.Accept
diff --git a/contrib/go/_std_1.20/src/internal/poll/hook_windows.go b/contrib/go/_std_1.20/src/internal/poll/hook_windows.go
new file mode 100644
index 0000000000..0bd950ebe4
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/hook_windows.go
@@ -0,0 +1,16 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package poll
+
+import "syscall"
+
+// CloseFunc is used to hook the close call.
+var CloseFunc func(syscall.Handle) error = syscall.Closesocket
+
+// AcceptFunc is used to hook the accept call.
+var AcceptFunc func(syscall.Handle, syscall.Handle, *byte, uint32, uint32, uint32, *uint32, *syscall.Overlapped) error = syscall.AcceptEx
+
+// ConnectExFunc is used to hook the ConnectEx call.
+var ConnectExFunc func(syscall.Handle, syscall.Sockaddr, *byte, uint32, *uint32, *syscall.Overlapped) error = syscall.ConnectEx
diff --git a/contrib/go/_std_1.20/src/internal/poll/iovec_unix.go b/contrib/go/_std_1.20/src/internal/poll/iovec_unix.go
new file mode 100644
index 0000000000..3f2833e728
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/iovec_unix.go
@@ -0,0 +1,13 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd
+
+package poll
+
+import "syscall"
+
+func newIovecWithBase(base *byte) syscall.Iovec {
+	return syscall.Iovec{Base: base}
+}
diff --git a/contrib/go/_std_1.20/src/internal/poll/sendfile_bsd.go b/contrib/go/_std_1.20/src/internal/poll/sendfile_bsd.go
new file mode 100644
index 0000000000..89315a8c67
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/sendfile_bsd.go
@@ -0,0 +1,59 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build darwin || dragonfly || freebsd
+
+package poll
+
+import "syscall"
+
+// maxSendfileSize is the largest chunk size we ask the kernel to copy
+// at a time.
+const maxSendfileSize int = 4 << 20
+
+// SendFile wraps the sendfile system call.
+func SendFile(dstFD *FD, src int, pos, remain int64) (int64, error) {
+	if err := dstFD.writeLock(); err != nil {
+		return 0, err
+	}
+	defer dstFD.writeUnlock()
+	if err := dstFD.pd.prepareWrite(dstFD.isFile); err != nil {
+		return 0, err
+	}
+
+	dst := dstFD.Sysfd
+	var written int64
+	var err error
+	for remain > 0 {
+		n := maxSendfileSize
+		if int64(n) > remain {
+			n = int(remain)
+		}
+		pos1 := pos
+		n, err1 := syscall.Sendfile(dst, src, &pos1, n)
+		if n > 0 {
+			pos += int64(n)
+			written += int64(n)
+			remain -= int64(n)
+		} else if n == 0 && err1 == nil {
+			break
+		}
+		if err1 == syscall.EINTR {
+			continue
+		}
+		if err1 == syscall.EAGAIN {
+			if err1 = dstFD.pd.waitWrite(dstFD.isFile); err1 == nil {
+				continue
+			}
+		}
+		if err1 != nil {
+			// This includes syscall.ENOSYS (no kernel
+			// support) and syscall.EINVAL (fd types which
+			// don't implement sendfile)
+			err = err1
+			break
+		}
+	}
+	return written, err
+}
diff --git a/contrib/go/_std_1.20/src/internal/poll/sendfile_linux.go b/contrib/go/_std_1.20/src/internal/poll/sendfile_linux.go
new file mode 100644
index 0000000000..cc31969a43
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/sendfile_linux.go
@@ -0,0 +1,59 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package poll
+
+import "syscall"
+
+// maxSendfileSize is the largest chunk size we ask the kernel to copy
+// at a time.
+const maxSendfileSize int = 4 << 20
+
+// SendFile wraps the sendfile system call.
+func SendFile(dstFD *FD, src int, remain int64) (int64, error, bool) {
+	if err := dstFD.writeLock(); err != nil {
+		return 0, err, false
+	}
+	defer dstFD.writeUnlock()
+	if err := dstFD.pd.prepareWrite(dstFD.isFile); err != nil {
+		return 0, err, false
+	}
+
+	dst := dstFD.Sysfd
+	var (
+		written int64
+		err     error
+		handled = true
+	)
+	for remain > 0 {
+		n := maxSendfileSize
+		if int64(n) > remain {
+			n = int(remain)
+		}
+		n, err1 := syscall.Sendfile(dst, src, nil, n)
+		if n > 0 {
+			written += int64(n)
+			remain -= int64(n)
+		} else if n == 0 && err1 == nil {
+			break
+		}
+		if err1 == syscall.EINTR {
+			continue
+		}
+		if err1 == syscall.EAGAIN {
+			if err1 = dstFD.pd.waitWrite(dstFD.isFile); err1 == nil {
+				continue
+			}
+		}
+		if err1 != nil {
+			// This includes syscall.ENOSYS (no kernel
+			// support) and syscall.EINVAL (fd types which
+			// don't implement sendfile)
+			err = err1
+			handled = false
+			break
+		}
+	}
+	return written, err, handled
+}
diff --git a/contrib/go/_std_1.20/src/internal/poll/sendfile_windows.go b/contrib/go/_std_1.20/src/internal/poll/sendfile_windows.go
new file mode 100644
index 0000000000..50c3ee86c0
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/sendfile_windows.go
@@ -0,0 +1,81 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package poll
+
+import (
+	"io"
+	"syscall"
+)
+
+// SendFile wraps the TransmitFile call.
+func SendFile(fd *FD, src syscall.Handle, n int64) (written int64, err error) {
+	if fd.kind == kindPipe {
+		// TransmitFile does not work with pipes
+		return 0, syscall.ESPIPE
+	}
+
+	if err := fd.writeLock(); err != nil {
+		return 0, err
+	}
+	defer fd.writeUnlock()
+
+	o := &fd.wop
+	o.handle = src
+
+	// TODO(brainman): skip calling syscall.Seek if OS allows it
+	curpos, err := syscall.Seek(o.handle, 0, io.SeekCurrent)
+	if err != nil {
+		return 0, err
+	}
+
+	if n <= 0 { // We don't know the size of the file so infer it.
+		// Find the number of bytes offset from curpos until the end of the file.
+		n, err = syscall.Seek(o.handle, -curpos, io.SeekEnd)
+		if err != nil {
+			return
+		}
+		// Now seek back to the original position.
+		if _, err = syscall.Seek(o.handle, curpos, io.SeekStart); err != nil {
+			return
+		}
+	}
+
+	// TransmitFile can be invoked in one call with at most
+	// 2,147,483,646 bytes: the maximum value for a 32-bit integer minus 1.
+	// See https://docs.microsoft.com/en-us/windows/win32/api/mswsock/nf-mswsock-transmitfile
+	const maxChunkSizePerCall = int64(0x7fffffff - 1)
+
+	for n > 0 {
+		chunkSize := maxChunkSizePerCall
+		if chunkSize > n {
+			chunkSize = n
+		}
+
+		o.qty = uint32(chunkSize)
+		o.o.Offset = uint32(curpos)
+		o.o.OffsetHigh = uint32(curpos >> 32)
+
+		nw, err := execIO(o, func(o *operation) error {
+			return syscall.TransmitFile(o.fd.Sysfd, o.handle, o.qty, 0, &o.o, nil, syscall.TF_WRITE_BEHIND)
+		})
+		if err != nil {
+			return written, err
+		}
+
+		curpos += int64(nw)
+
+		// Some versions of Windows (Windows 10 1803) do not set
+		// file position after TransmitFile completes.
+		// So just use Seek to set file position.
+		if _, err = syscall.Seek(o.handle, curpos, io.SeekStart); err != nil {
+			return written, err
+		}
+
+		n -= int64(nw)
+		written += int64(nw)
+	}
+
+	return
+}
diff --git a/contrib/go/_std_1.20/src/internal/poll/sock_cloexec.go b/contrib/go/_std_1.20/src/internal/poll/sock_cloexec.go
new file mode 100644
index 0000000000..f5be2aa5f2
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/sock_cloexec.go
@@ -0,0 +1,22 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements accept for platforms that provide a fast path for
+// setting SetNonblock and CloseOnExec.
+
+//go:build dragonfly || freebsd || (linux && !arm) || netbsd || openbsd || solaris
+
+package poll
+
+import "syscall"
+
+// Wrapper around the accept system call that marks the returned file
+// descriptor as nonblocking and close-on-exec.
+func accept(s int) (int, syscall.Sockaddr, string, error) {
+	ns, sa, err := Accept4Func(s, syscall.SOCK_NONBLOCK|syscall.SOCK_CLOEXEC)
+	if err != nil {
+		return -1, sa, "accept4", err
+	}
+	return ns, sa, "", nil
+}
diff --git a/contrib/go/_std_1.20/src/internal/poll/sockopt.go b/contrib/go/_std_1.20/src/internal/poll/sockopt.go
new file mode 100644
index 0000000000..a7c9d115b4
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/sockopt.go
@@ -0,0 +1,36 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build unix || windows
+
+package poll
+
+import "syscall"
+
+// SetsockoptInt wraps the setsockopt network call with an int argument.
+func (fd *FD) SetsockoptInt(level, name, arg int) error {
+	if err := fd.incref(); err != nil {
+		return err
+	}
+	defer fd.decref()
+	return syscall.SetsockoptInt(fd.Sysfd, level, name, arg)
+}
+
+// SetsockoptInet4Addr wraps the setsockopt network call with an IPv4 address.
+func (fd *FD) SetsockoptInet4Addr(level, name int, arg [4]byte) error {
+	if err := fd.incref(); err != nil {
+		return err
+	}
+	defer fd.decref()
+	return syscall.SetsockoptInet4Addr(fd.Sysfd, level, name, arg)
+}
+
+// SetsockoptLinger wraps the setsockopt network call with a Linger argument.
+func (fd *FD) SetsockoptLinger(level, name int, l *syscall.Linger) error {
+	if err := fd.incref(); err != nil {
+		return err
+	}
+	defer fd.decref()
+	return syscall.SetsockoptLinger(fd.Sysfd, level, name, l)
+}
diff --git a/contrib/go/_std_1.20/src/internal/poll/sockopt_linux.go b/contrib/go/_std_1.20/src/internal/poll/sockopt_linux.go
new file mode 100644
index 0000000000..bc79c350ac
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/sockopt_linux.go
@@ -0,0 +1,16 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package poll
+
+import "syscall"
+
+// SetsockoptIPMreqn wraps the setsockopt network call with an IPMreqn argument.
+func (fd *FD) SetsockoptIPMreqn(level, name int, mreq *syscall.IPMreqn) error {
+	if err := fd.incref(); err != nil {
+		return err
+	}
+	defer fd.decref()
+	return syscall.SetsockoptIPMreqn(fd.Sysfd, level, name, mreq)
+}
diff --git a/contrib/go/_std_1.20/src/internal/poll/sockopt_unix.go b/contrib/go/_std_1.20/src/internal/poll/sockopt_unix.go
new file mode 100644
index 0000000000..9cba44da9d
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/sockopt_unix.go
@@ -0,0 +1,18 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build unix
+
+package poll
+
+import "syscall"
+
+// SetsockoptByte wraps the setsockopt network call with a byte argument.
+func (fd *FD) SetsockoptByte(level, name int, arg byte) error {
+	if err := fd.incref(); err != nil {
+		return err
+	}
+	defer fd.decref()
+	return syscall.SetsockoptByte(fd.Sysfd, level, name, arg)
+}
diff --git a/contrib/go/_std_1.20/src/internal/poll/sockopt_windows.go b/contrib/go/_std_1.20/src/internal/poll/sockopt_windows.go
new file mode 100644
index 0000000000..dd5fb70bab
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/sockopt_windows.go
@@ -0,0 +1,25 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package poll
+
+import "syscall"
+
+// Setsockopt wraps the setsockopt network call.
+func (fd *FD) Setsockopt(level, optname int32, optval *byte, optlen int32) error {
+	if err := fd.incref(); err != nil {
+		return err
+	}
+	defer fd.decref()
+	return syscall.Setsockopt(fd.Sysfd, level, optname, optval, optlen)
+}
+
+// WSAIoctl wraps the WSAIoctl network call.
+func (fd *FD) WSAIoctl(iocc uint32, inbuf *byte, cbif uint32, outbuf *byte, cbob uint32, cbbr *uint32, overlapped *syscall.Overlapped, completionRoutine uintptr) error {
+	if err := fd.incref(); err != nil {
+		return err
+	}
+	defer fd.decref()
+	return syscall.WSAIoctl(fd.Sysfd, iocc, inbuf, cbif, outbuf, cbob, cbbr, overlapped, completionRoutine)
+}
diff --git a/contrib/go/_std_1.20/src/internal/poll/sockoptip.go b/contrib/go/_std_1.20/src/internal/poll/sockoptip.go
new file mode 100644
index 0000000000..41955e1fda
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/sockoptip.go
@@ -0,0 +1,27 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build unix || windows
+
+package poll
+
+import "syscall"
+
+// SetsockoptIPMreq wraps the setsockopt network call with an IPMreq argument.
+func (fd *FD) SetsockoptIPMreq(level, name int, mreq *syscall.IPMreq) error {
+	if err := fd.incref(); err != nil {
+		return err
+	}
+	defer fd.decref()
+	return syscall.SetsockoptIPMreq(fd.Sysfd, level, name, mreq)
+}
+
+// SetsockoptIPv6Mreq wraps the setsockopt network call with an IPv6Mreq argument.
+func (fd *FD) SetsockoptIPv6Mreq(level, name int, mreq *syscall.IPv6Mreq) error {
+	if err := fd.incref(); err != nil {
+		return err
+	}
+	defer fd.decref()
+	return syscall.SetsockoptIPv6Mreq(fd.Sysfd, level, name, mreq)
+}
diff --git a/contrib/go/_std_1.20/src/internal/poll/splice_linux.go b/contrib/go/_std_1.20/src/internal/poll/splice_linux.go
new file mode 100644
index 0000000000..96cbe4a312
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/splice_linux.go
@@ -0,0 +1,231 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package poll
+
+import (
+	"runtime"
+	"sync"
+	"syscall"
+	"unsafe"
+)
+
+const (
+	// spliceNonblock makes calls to splice(2) non-blocking.
+	spliceNonblock = 0x2
+
+	// maxSpliceSize is the maximum amount of data Splice asks
+	// the kernel to move in a single call to splice(2).
+	// We use 1MB as Splice writes data through a pipe, and 1MB is the default maximum pipe buffer size,
+	// which is determined by /proc/sys/fs/pipe-max-size.
+	maxSpliceSize = 1 << 20
+)
+
+// Splice transfers at most remain bytes of data from src to dst, using the
+// splice system call to minimize copies of data from and to userspace.
+//
+// Splice gets a pipe buffer from the pool or creates a new one if needed, to serve as a buffer for the data transfer.
+// src and dst must both be stream-oriented sockets.
+//
+// If err != nil, sc is the system call which caused the error.
+func Splice(dst, src *FD, remain int64) (written int64, handled bool, sc string, err error) {
+	p, sc, err := getPipe()
+	if err != nil {
+		return 0, false, sc, err
+	}
+	defer putPipe(p)
+	var inPipe, n int
+	for err == nil && remain > 0 {
+		max := maxSpliceSize
+		if int64(max) > remain {
+			max = int(remain)
+		}
+		inPipe, err = spliceDrain(p.wfd, src, max)
+		// The operation is considered handled if splice returns no
+		// error, or an error other than EINVAL. An EINVAL means the
+		// kernel does not support splice for the socket type of src.
+		// The failed syscall does not consume any data so it is safe
+		// to fall back to a generic copy.
+		//
+		// spliceDrain should never return EAGAIN, so if err != nil,
+		// Splice cannot continue.
+		//
+		// If inPipe == 0 && err == nil, src is at EOF, and the
+		// transfer is complete.
+		handled = handled || (err != syscall.EINVAL)
+		if err != nil || inPipe == 0 {
+			break
+		}
+		p.data += inPipe
+
+		n, err = splicePump(dst, p.rfd, inPipe)
+		if n > 0 {
+			written += int64(n)
+			remain -= int64(n)
+			p.data -= n
+		}
+	}
+	if err != nil {
+		return written, handled, "splice", err
+	}
+	return written, true, "", nil
+}
+
+// spliceDrain moves data from a socket to a pipe.
+//
+// Invariant: when entering spliceDrain, the pipe is empty. It is either in its
+// initial state, or splicePump has emptied it previously.
+//
+// Given this, spliceDrain can reasonably assume that the pipe is ready for
+// writing, so if splice returns EAGAIN, it must be because the socket is not
+// ready for reading.
+//
+// If spliceDrain returns (0, nil), src is at EOF.
+func spliceDrain(pipefd int, sock *FD, max int) (int, error) {
+	if err := sock.readLock(); err != nil {
+		return 0, err
+	}
+	defer sock.readUnlock()
+	if err := sock.pd.prepareRead(sock.isFile); err != nil {
+		return 0, err
+	}
+	for {
+		n, err := splice(pipefd, sock.Sysfd, max, spliceNonblock)
+		if err == syscall.EINTR {
+			continue
+		}
+		if err != syscall.EAGAIN {
+			return n, err
+		}
+		if err := sock.pd.waitRead(sock.isFile); err != nil {
+			return n, err
+		}
+	}
+}
+
+// splicePump moves all the buffered data from a pipe to a socket.
+//
+// Invariant: when entering splicePump, there are exactly inPipe
+// bytes of data in the pipe, from a previous call to spliceDrain.
+//
+// By analogy to the condition from spliceDrain, splicePump
+// only needs to poll the socket for readiness, if splice returns
+// EAGAIN.
+//
+// If splicePump cannot move all the data in a single call to
+// splice(2), it loops over the buffered data until it has written
+// all of it to the socket. This behavior is similar to the Write
+// step of an io.Copy in userspace.
+func splicePump(sock *FD, pipefd int, inPipe int) (int, error) {
+	if err := sock.writeLock(); err != nil {
+		return 0, err
+	}
+	defer sock.writeUnlock()
+	if err := sock.pd.prepareWrite(sock.isFile); err != nil {
+		return 0, err
+	}
+	written := 0
+	for inPipe > 0 {
+		n, err := splice(sock.Sysfd, pipefd, inPipe, spliceNonblock)
+		// Here, the condition n == 0 && err == nil should never be
+		// observed, since Splice controls the write side of the pipe.
+		if n > 0 {
+			inPipe -= n
+			written += n
+			continue
+		}
+		if err != syscall.EAGAIN {
+			return written, err
+		}
+		if err := sock.pd.waitWrite(sock.isFile); err != nil {
+			return written, err
+		}
+	}
+	return written, nil
+}
+
+// splice wraps the splice system call. Since the current implementation
+// only uses splice on sockets and pipes, the offset arguments are unused.
+// splice returns int instead of int64, because callers never ask it to
+// move more data in a single call than can fit in an int32.
+func splice(out int, in int, max int, flags int) (int, error) {
+	n, err := syscall.Splice(in, nil, out, nil, max, flags)
+	return int(n), err
+}
+
+type splicePipeFields struct {
+	rfd  int
+	wfd  int
+	data int
+}
+
+type splicePipe struct {
+	splicePipeFields
+
+	// We want to use a finalizer, so ensure that the size is
+	// large enough to not use the tiny allocator.
+	_ [24 - unsafe.Sizeof(splicePipeFields{})%24]byte
+}
+
+// splicePipePool caches pipes to avoid high-frequency construction and destruction of pipe buffers.
+// The garbage collector will free all pipes in the sync.Pool periodically, thus we need to set up
+// a finalizer for each pipe to close its file descriptors before the actual GC.
+var splicePipePool = sync.Pool{New: newPoolPipe}
+
+func newPoolPipe() any {
+	// Discard the error which occurred during the creation of pipe buffer,
+	// redirecting the data transmission to the conventional way utilizing read() + write() as a fallback.
+	p := newPipe()
+	if p == nil {
+		return nil
+	}
+	runtime.SetFinalizer(p, destroyPipe)
+	return p
+}
+
+// getPipe tries to acquire a pipe buffer from the pool or create a new one with newPipe() if it gets nil from the cache.
+//
+// Note that it may fail to create a new pipe buffer by newPipe(), in which case getPipe() will return a generic error
+// and system call name splice in a string as the indication.
+func getPipe() (*splicePipe, string, error) {
+	v := splicePipePool.Get()
+	if v == nil {
+		return nil, "splice", syscall.EINVAL
+	}
+	return v.(*splicePipe), "", nil
+}
+
+func putPipe(p *splicePipe) {
+	// If there is still data left in the pipe,
+	// then close and discard it instead of putting it back into the pool.
+	if p.data != 0 {
+		runtime.SetFinalizer(p, nil)
+		destroyPipe(p)
+		return
+	}
+	splicePipePool.Put(p)
+}
+
+// newPipe sets up a pipe for a splice operation.
+func newPipe() *splicePipe {
+	var fds [2]int
+	if err := syscall.Pipe2(fds[:], syscall.O_CLOEXEC|syscall.O_NONBLOCK); err != nil {
+		return nil
+	}
+
+	// Splice will loop writing maxSpliceSize bytes from the source to the pipe,
+	// and then write those bytes from the pipe to the destination.
+	// Set the pipe buffer size to maxSpliceSize to optimize that.
+	// Ignore errors here, as a smaller buffer size will work,
+	// although it will require more system calls.
+	fcntl(fds[0], syscall.F_SETPIPE_SZ, maxSpliceSize)
+
+	return &splicePipe{splicePipeFields: splicePipeFields{rfd: fds[0], wfd: fds[1]}}
+}
+
+// destroyPipe destroys a pipe.
+func destroyPipe(p *splicePipe) {
+	CloseFunc(p.rfd)
+	CloseFunc(p.wfd)
+}
diff --git a/contrib/go/_std_1.20/src/internal/poll/sys_cloexec.go b/contrib/go/_std_1.20/src/internal/poll/sys_cloexec.go
new file mode 100644
index 0000000000..7cd80019f4
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/sys_cloexec.go
@@ -0,0 +1,36 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements accept for platforms that do not provide a fast path for
+// setting SetNonblock and CloseOnExec.
+
+//go:build aix || darwin || (js && wasm)
+
+package poll
+
+import (
+	"syscall"
+)
+
+// Wrapper around the accept system call that marks the returned file
+// descriptor as nonblocking and close-on-exec.
+func accept(s int) (int, syscall.Sockaddr, string, error) {
+	// See ../syscall/exec_unix.go for description of ForkLock.
+	// It is probably okay to hold the lock across syscall.Accept
+	// because we have put fd.sysfd into non-blocking mode.
+	// However, a call to the File method will put it back into
+	// blocking mode. We can't take that risk, so no use of ForkLock here.
+	ns, sa, err := AcceptFunc(s)
+	if err == nil {
+		syscall.CloseOnExec(ns)
+	}
+	if err != nil {
+		return -1, nil, "accept", err
+	}
+	if err = syscall.SetNonblock(ns, true); err != nil {
+		CloseFunc(ns)
+		return -1, nil, "setnonblock", err
+	}
+	return ns, sa, "", nil
+}
diff --git a/contrib/go/_std_1.20/src/internal/poll/writev.go b/contrib/go/_std_1.20/src/internal/poll/writev.go
new file mode 100644
index 0000000000..75c8b642b5
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/writev.go
@@ -0,0 +1,92 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build unix
+
+package poll
+
+import (
+	"io"
+	"runtime"
+	"syscall"
+)
+
+// Writev wraps the writev system call.
+func (fd *FD) Writev(v *[][]byte) (int64, error) {
+	if err := fd.writeLock(); err != nil {
+		return 0, err
+	}
+	defer fd.writeUnlock()
+	if err := fd.pd.prepareWrite(fd.isFile); err != nil {
+		return 0, err
+	}
+
+	var iovecs []syscall.Iovec
+	if fd.iovecs != nil {
+		iovecs = *fd.iovecs
+	}
+	// TODO: read from sysconf(_SC_IOV_MAX)? The Linux default is
+	// 1024 and this seems conservative enough for now. Darwin's
+	// UIO_MAXIOV also seems to be 1024.
+	maxVec := 1024
+	if runtime.GOOS == "aix" || runtime.GOOS == "solaris" {
+		// IOV_MAX is set to XOPEN_IOV_MAX on AIX and Solaris.
+		maxVec = 16
+	}
+
+	var n int64
+	var err error
+	for len(*v) > 0 {
+		iovecs = iovecs[:0]
+		for _, chunk := range *v {
+			if len(chunk) == 0 {
+				continue
+			}
+			iovecs = append(iovecs, newIovecWithBase(&chunk[0]))
+			if fd.IsStream && len(chunk) > 1<<30 {
+				iovecs[len(iovecs)-1].SetLen(1 << 30)
+				break // continue chunk on next writev
+			}
+			iovecs[len(iovecs)-1].SetLen(len(chunk))
+			if len(iovecs) == maxVec {
+				break
+			}
+		}
+		if len(iovecs) == 0 {
+			break
+		}
+		if fd.iovecs == nil {
+			fd.iovecs = new([]syscall.Iovec)
+		}
+		*fd.iovecs = iovecs // cache
+
+		var wrote uintptr
+		wrote, err = writev(fd.Sysfd, iovecs)
+		if wrote == ^uintptr(0) {
+			wrote = 0
+		}
+		TestHookDidWritev(int(wrote))
+		n += int64(wrote)
+		consume(v, int64(wrote))
+		for i := range iovecs {
+			iovecs[i] = syscall.Iovec{}
+		}
+		if err != nil {
+			if err == syscall.EINTR {
+				continue
+			}
+			if err == syscall.EAGAIN {
+				if err = fd.pd.waitWrite(fd.isFile); err == nil {
+					continue
+				}
+			}
+			break
+		}
+		if n == 0 {
+			err = io.ErrUnexpectedEOF
+			break
+		}
+	}
+	return n, err
+}
diff --git a/contrib/go/_std_1.20/src/internal/poll/ya.make b/contrib/go/_std_1.20/src/internal/poll/ya.make
new file mode 100644
index 0000000000..bc94f38a4a
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/poll/ya.make
@@ -0,0 +1,60 @@
+GO_LIBRARY()
+
+SRCS(
+    fd.go
+    fd_mutex.go
+    fd_poll_runtime.go
+    fd_posix.go
+    sockopt.go
+    sockoptip.go
+)
+
+IF (OS_DARWIN)
+    SRCS(
+        errno_unix.go
+        fcntl_libc.go
+        fd_fsync_darwin.go
+        fd_opendir_darwin.go
+        fd_unix.go
+        fd_writev_libc.go
+        hook_unix.go
+        iovec_unix.go
+        sendfile_bsd.go
+        sockopt_unix.go
+        sys_cloexec.go
+        writev.go
+    )
+ENDIF()
+
+IF (OS_LINUX)
+    SRCS(
+        copy_file_range_linux.go
+        errno_unix.go
+        fcntl_syscall.go
+        fd_fsync_posix.go
+        fd_unix.go
+        fd_writev_unix.go
+        hook_cloexec.go
+        hook_unix.go
+        iovec_unix.go
+        sendfile_linux.go
+        sock_cloexec.go
+        sockopt_linux.go
+        sockopt_unix.go
+        splice_linux.go
+        writev.go
+    )
+ENDIF()
+
+IF (OS_WINDOWS)
+    SRCS(
+        errno_windows.go
+        fd_fsync_windows.go
+        fd_windows.go
+        hook_windows.go
+        sendfile_windows.go
+        sockopt_windows.go
+    )
+ENDIF()
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/profile/encode.go b/contrib/go/_std_1.20/src/internal/profile/encode.go
new file mode 100644
index 0000000000..77d77f1dfb
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/profile/encode.go
@@ -0,0 +1,482 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package profile
+
+import (
+	"errors"
+	"fmt"
+	"sort"
+)
+
+func (p *Profile) decoder() []decoder {
+	return profileDecoder
+}
+
+// preEncode populates the unexported fields to be used by encode
+// (with suffix X) from the corresponding exported fields. The
+// exported fields are cleared up to facilitate testing.
+func (p *Profile) preEncode() {
+	strings := make(map[string]int)
+	addString(strings, "")
+
+	for _, st := range p.SampleType {
+		st.typeX = addString(strings, st.Type)
+		st.unitX = addString(strings, st.Unit)
+	}
+
+	for _, s := range p.Sample {
+		s.labelX = nil
+		var keys []string
+		for k := range s.Label {
+			keys = append(keys, k)
+		}
+		sort.Strings(keys)
+		for _, k := range keys {
+			vs := s.Label[k]
+			for _, v := range vs {
+				s.labelX = append(s.labelX,
+					Label{
+						keyX: addString(strings, k),
+						strX: addString(strings, v),
+					},
+				)
+			}
+		}
+		var numKeys []string
+		for k := range s.NumLabel {
+			numKeys = append(numKeys, k)
+		}
+		sort.Strings(numKeys)
+		for _, k := range numKeys {
+			vs := s.NumLabel[k]
+			for _, v := range vs {
+				s.labelX = append(s.labelX,
+					Label{
+						keyX: addString(strings, k),
+						numX: v,
+					},
+				)
+			}
+		}
+		s.locationIDX = nil
+		for _, l := range s.Location {
+			s.locationIDX = append(s.locationIDX, l.ID)
+		}
+	}
+
+	for _, m := range p.Mapping {
+		m.fileX = addString(strings, m.File)
+		m.buildIDX = addString(strings, m.BuildID)
+	}
+
+	for _, l := range p.Location {
+		for i, ln := range l.Line {
+			if ln.Function != nil {
+				l.Line[i].functionIDX = ln.Function.ID
+			} else {
+				l.Line[i].functionIDX = 0
+			}
+		}
+		if l.Mapping != nil {
+			l.mappingIDX = l.Mapping.ID
+		} else {
+			l.mappingIDX = 0
+		}
+	}
+	for _, f := range p.Function {
+		f.nameX = addString(strings, f.Name)
+		f.systemNameX = addString(strings, f.SystemName)
+		f.filenameX = addString(strings, f.Filename)
+	}
+
+	p.dropFramesX = addString(strings, p.DropFrames)
+	p.keepFramesX = addString(strings, p.KeepFrames)
+
+	if pt := p.PeriodType; pt != nil {
+		pt.typeX = addString(strings, pt.Type)
+		pt.unitX = addString(strings, pt.Unit)
+	}
+
+	p.stringTable = make([]string, len(strings))
+	for s, i := range strings {
+		p.stringTable[i] = s
+	}
+}
+
+func (p *Profile) encode(b *buffer) {
+	for _, x := range p.SampleType {
+		encodeMessage(b, 1, x)
+	}
+	for _, x := range p.Sample {
+		encodeMessage(b, 2, x)
+	}
+	for _, x := range p.Mapping {
+		encodeMessage(b, 3, x)
+	}
+	for _, x := range p.Location {
+		encodeMessage(b, 4, x)
+	}
+	for _, x := range p.Function {
+		encodeMessage(b, 5, x)
+	}
+	encodeStrings(b, 6, p.stringTable)
+	encodeInt64Opt(b, 7, p.dropFramesX)
+	encodeInt64Opt(b, 8, p.keepFramesX)
+	encodeInt64Opt(b, 9, p.TimeNanos)
+	encodeInt64Opt(b, 10, p.DurationNanos)
+	if pt := p.PeriodType; pt != nil && (pt.typeX != 0 || pt.unitX != 0) {
+		encodeMessage(b, 11, p.PeriodType)
+	}
+	encodeInt64Opt(b, 12, p.Period)
+}
+
+var profileDecoder = []decoder{
+	nil, // 0
+	// repeated ValueType sample_type = 1
+	func(b *buffer, m message) error {
+		x := new(ValueType)
+		pp := m.(*Profile)
+		pp.SampleType = append(pp.SampleType, x)
+		return decodeMessage(b, x)
+	},
+	// repeated Sample sample = 2
+	func(b *buffer, m message) error {
+		x := new(Sample)
+		pp := m.(*Profile)
+		pp.Sample = append(pp.Sample, x)
+		return decodeMessage(b, x)
+	},
+	// repeated Mapping mapping = 3
+	func(b *buffer, m message) error {
+		x := new(Mapping)
+		pp := m.(*Profile)
+		pp.Mapping = append(pp.Mapping, x)
+		return decodeMessage(b, x)
+	},
+	// repeated Location location = 4
+	func(b *buffer, m message) error {
+		x := new(Location)
+		pp := m.(*Profile)
+		pp.Location = append(pp.Location, x)
+		return decodeMessage(b, x)
+	},
+	// repeated Function function = 5
+	func(b *buffer, m message) error {
+		x := new(Function)
+		pp := m.(*Profile)
+		pp.Function = append(pp.Function, x)
+		return decodeMessage(b, x)
+	},
+	// repeated string string_table = 6
+	func(b *buffer, m message) error {
+		err := decodeStrings(b, &m.(*Profile).stringTable)
+		if err != nil {
+			return err
+		}
+		if m.(*Profile).stringTable[0] != "" {
+			return errors.New("string_table[0] must be ''")
+		}
+		return nil
+	},
+	// repeated int64 drop_frames = 7
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*Profile).dropFramesX) },
+	// repeated int64 keep_frames = 8
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*Profile).keepFramesX) },
+	// repeated int64 time_nanos = 9
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*Profile).TimeNanos) },
+	// repeated int64 duration_nanos = 10
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*Profile).DurationNanos) },
+	// optional string period_type = 11
+	func(b *buffer, m message) error {
+		x := new(ValueType)
+		pp := m.(*Profile)
+		pp.PeriodType = x
+		return decodeMessage(b, x)
+	},
+	// repeated int64 period = 12
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*Profile).Period) },
+	// repeated int64 comment = 13
+	func(b *buffer, m message) error { return decodeInt64s(b, &m.(*Profile).commentX) },
+	// int64 defaultSampleType = 14
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*Profile).defaultSampleTypeX) },
+}
+
+// postDecode takes the unexported fields populated by decode (with
+// suffix X) and populates the corresponding exported fields.
+// The unexported fields are cleared up to facilitate testing.
+func (p *Profile) postDecode() error {
+	var err error
+
+	mappings := make(map[uint64]*Mapping)
+	for _, m := range p.Mapping {
+		m.File, err = getString(p.stringTable, &m.fileX, err)
+		m.BuildID, err = getString(p.stringTable, &m.buildIDX, err)
+		mappings[m.ID] = m
+	}
+
+	functions := make(map[uint64]*Function)
+	for _, f := range p.Function {
+		f.Name, err = getString(p.stringTable, &f.nameX, err)
+		f.SystemName, err = getString(p.stringTable, &f.systemNameX, err)
+		f.Filename, err = getString(p.stringTable, &f.filenameX, err)
+		functions[f.ID] = f
+	}
+
+	locations := make(map[uint64]*Location)
+	for _, l := range p.Location {
+		l.Mapping = mappings[l.mappingIDX]
+		l.mappingIDX = 0
+		for i, ln := range l.Line {
+			if id := ln.functionIDX; id != 0 {
+				l.Line[i].Function = functions[id]
+				if l.Line[i].Function == nil {
+					return fmt.Errorf("Function ID %d not found", id)
+				}
+				l.Line[i].functionIDX = 0
+			}
+		}
+		locations[l.ID] = l
+	}
+
+	for _, st := range p.SampleType {
+		st.Type, err = getString(p.stringTable, &st.typeX, err)
+		st.Unit, err = getString(p.stringTable, &st.unitX, err)
+	}
+
+	for _, s := range p.Sample {
+		labels := make(map[string][]string)
+		numLabels := make(map[string][]int64)
+		for _, l := range s.labelX {
+			var key, value string
+			key, err = getString(p.stringTable, &l.keyX, err)
+			if l.strX != 0 {
+				value, err = getString(p.stringTable, &l.strX, err)
+				labels[key] = append(labels[key], value)
+			} else {
+				numLabels[key] = append(numLabels[key], l.numX)
+			}
+		}
+		if len(labels) > 0 {
+			s.Label = labels
+		}
+		if len(numLabels) > 0 {
+			s.NumLabel = numLabels
+		}
+		s.Location = nil
+		for _, lid := range s.locationIDX {
+			s.Location = append(s.Location, locations[lid])
+		}
+		s.locationIDX = nil
+	}
+
+	p.DropFrames, err = getString(p.stringTable, &p.dropFramesX, err)
+	p.KeepFrames, err = getString(p.stringTable, &p.keepFramesX, err)
+
+	if pt := p.PeriodType; pt == nil {
+		p.PeriodType = &ValueType{}
+	}
+
+	if pt := p.PeriodType; pt != nil {
+		pt.Type, err = getString(p.stringTable, &pt.typeX, err)
+		pt.Unit, err = getString(p.stringTable, &pt.unitX, err)
+	}
+	for _, i := range p.commentX {
+		var c string
+		c, err = getString(p.stringTable, &i, err)
+		p.Comments = append(p.Comments, c)
+	}
+
+	p.commentX = nil
+	p.DefaultSampleType, err = getString(p.stringTable, &p.defaultSampleTypeX, err)
+	p.stringTable = nil
+	return nil
+}
+
+func (p *ValueType) decoder() []decoder {
+	return valueTypeDecoder
+}
+
+func (p *ValueType) encode(b *buffer) {
+	encodeInt64Opt(b, 1, p.typeX)
+	encodeInt64Opt(b, 2, p.unitX)
+}
+
+var valueTypeDecoder = []decoder{
+	nil, // 0
+	// optional int64 type = 1
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*ValueType).typeX) },
+	// optional int64 unit = 2
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*ValueType).unitX) },
+}
+
+func (p *Sample) decoder() []decoder {
+	return sampleDecoder
+}
+
+func (p *Sample) encode(b *buffer) {
+	encodeUint64s(b, 1, p.locationIDX)
+	for _, x := range p.Value {
+		encodeInt64(b, 2, x)
+	}
+	for _, x := range p.labelX {
+		encodeMessage(b, 3, x)
+	}
+}
+
+var sampleDecoder = []decoder{
+	nil, // 0
+	// repeated uint64 location = 1
+	func(b *buffer, m message) error { return decodeUint64s(b, &m.(*Sample).locationIDX) },
+	// repeated int64 value = 2
+	func(b *buffer, m message) error { return decodeInt64s(b, &m.(*Sample).Value) },
+	// repeated Label label = 3
+	func(b *buffer, m message) error {
+		s := m.(*Sample)
+		n := len(s.labelX)
+		s.labelX = append(s.labelX, Label{})
+		return decodeMessage(b, &s.labelX[n])
+	},
+}
+
+func (p Label) decoder() []decoder {
+	return labelDecoder
+}
+
+func (p Label) encode(b *buffer) {
+	encodeInt64Opt(b, 1, p.keyX)
+	encodeInt64Opt(b, 2, p.strX)
+	encodeInt64Opt(b, 3, p.numX)
+}
+
+var labelDecoder = []decoder{
+	nil, // 0
+	// optional int64 key = 1
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*Label).keyX) },
+	// optional int64 str = 2
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*Label).strX) },
+	// optional int64 num = 3
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*Label).numX) },
+}
+
+func (p *Mapping) decoder() []decoder {
+	return mappingDecoder
+}
+
+func (p *Mapping) encode(b *buffer) {
+	encodeUint64Opt(b, 1, p.ID)
+	encodeUint64Opt(b, 2, p.Start)
+	encodeUint64Opt(b, 3, p.Limit)
+	encodeUint64Opt(b, 4, p.Offset)
+	encodeInt64Opt(b, 5, p.fileX)
+	encodeInt64Opt(b, 6, p.buildIDX)
+	encodeBoolOpt(b, 7, p.HasFunctions)
+	encodeBoolOpt(b, 8, p.HasFilenames)
+	encodeBoolOpt(b, 9, p.HasLineNumbers)
+	encodeBoolOpt(b, 10, p.HasInlineFrames)
+}
+
+var mappingDecoder = []decoder{
+	nil, // 0
+	func(b *buffer, m message) error { return decodeUint64(b, &m.(*Mapping).ID) },            // optional uint64 id = 1
+	func(b *buffer, m message) error { return decodeUint64(b, &m.(*Mapping).Start) },         // optional uint64 memory_offset = 2
+	func(b *buffer, m message) error { return decodeUint64(b, &m.(*Mapping).Limit) },         // optional uint64 memory_limit = 3
+	func(b *buffer, m message) error { return decodeUint64(b, &m.(*Mapping).Offset) },        // optional uint64 file_offset = 4
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*Mapping).fileX) },          // optional int64 filename = 5
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*Mapping).buildIDX) },       // optional int64 build_id = 6
+	func(b *buffer, m message) error { return decodeBool(b, &m.(*Mapping).HasFunctions) },    // optional bool has_functions = 7
+	func(b *buffer, m message) error { return decodeBool(b, &m.(*Mapping).HasFilenames) },    // optional bool has_filenames = 8
+	func(b *buffer, m message) error { return decodeBool(b, &m.(*Mapping).HasLineNumbers) },  // optional bool has_line_numbers = 9
+	func(b *buffer, m message) error { return decodeBool(b, &m.(*Mapping).HasInlineFrames) }, // optional bool has_inline_frames = 10
+}
+
+func (p *Location) decoder() []decoder {
+	return locationDecoder
+}
+
+func (p *Location) encode(b *buffer) {
+	encodeUint64Opt(b, 1, p.ID)
+	encodeUint64Opt(b, 2, p.mappingIDX)
+	encodeUint64Opt(b, 3, p.Address)
+	for i := range p.Line {
+		encodeMessage(b, 4, &p.Line[i])
+	}
+}
+
+var locationDecoder = []decoder{
+	nil, // 0
+	func(b *buffer, m message) error { return decodeUint64(b, &m.(*Location).ID) },         // optional uint64 id = 1;
+	func(b *buffer, m message) error { return decodeUint64(b, &m.(*Location).mappingIDX) }, // optional uint64 mapping_id = 2;
+	func(b *buffer, m message) error { return decodeUint64(b, &m.(*Location).Address) },    // optional uint64 address = 3;
+	func(b *buffer, m message) error { // repeated Line line = 4
+		pp := m.(*Location)
+		n := len(pp.Line)
+		pp.Line = append(pp.Line, Line{})
+		return decodeMessage(b, &pp.Line[n])
+	},
+}
+
+func (p *Line) decoder() []decoder {
+	return lineDecoder
+}
+
+func (p *Line) encode(b *buffer) {
+	encodeUint64Opt(b, 1, p.functionIDX)
+	encodeInt64Opt(b, 2, p.Line)
+}
+
+var lineDecoder = []decoder{
+	nil, // 0
+	// optional uint64 function_id = 1
+	func(b *buffer, m message) error { return decodeUint64(b, &m.(*Line).functionIDX) },
+	// optional int64 line = 2
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*Line).Line) },
+}
+
+func (p *Function) decoder() []decoder {
+	return functionDecoder
+}
+
+func (p *Function) encode(b *buffer) {
+	encodeUint64Opt(b, 1, p.ID)
+	encodeInt64Opt(b, 2, p.nameX)
+	encodeInt64Opt(b, 3, p.systemNameX)
+	encodeInt64Opt(b, 4, p.filenameX)
+	encodeInt64Opt(b, 5, p.StartLine)
+}
+
+var functionDecoder = []decoder{
+	nil, // 0
+	// optional uint64 id = 1
+	func(b *buffer, m message) error { return decodeUint64(b, &m.(*Function).ID) },
+	// optional int64 function_name = 2
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*Function).nameX) },
+	// optional int64 function_system_name = 3
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*Function).systemNameX) },
+	// repeated int64 filename = 4
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*Function).filenameX) },
+	// optional int64 start_line = 5
+	func(b *buffer, m message) error { return decodeInt64(b, &m.(*Function).StartLine) },
+}
+
+func addString(strings map[string]int, s string) int64 {
+	i, ok := strings[s]
+	if !ok {
+		i = len(strings)
+		strings[s] = i
+	}
+	return int64(i)
+}
+
+func getString(strings []string, strng *int64, err error) (string, error) {
+	if err != nil {
+		return "", err
+	}
+	s := int(*strng)
+	if s < 0 || s >= len(strings) {
+		return "", errMalformed
+	}
+	*strng = 0
+	return strings[s], nil
+}
diff --git a/contrib/go/_std_1.20/src/internal/profile/filter.go b/contrib/go/_std_1.20/src/internal/profile/filter.go
new file mode 100644
index 0000000000..141dd1f405
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/profile/filter.go
@@ -0,0 +1,158 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Implements methods to filter samples from profiles.
+
+package profile
+
+import "regexp"
+
+// FilterSamplesByName filters the samples in a profile and only keeps
+// samples where at least one frame matches focus but none match ignore.
+// Returns true is the corresponding regexp matched at least one sample.
+func (p *Profile) FilterSamplesByName(focus, ignore, hide *regexp.Regexp) (fm, im, hm bool) {
+	focusOrIgnore := make(map[uint64]bool)
+	hidden := make(map[uint64]bool)
+	for _, l := range p.Location {
+		if ignore != nil && l.matchesName(ignore) {
+			im = true
+			focusOrIgnore[l.ID] = false
+		} else if focus == nil || l.matchesName(focus) {
+			fm = true
+			focusOrIgnore[l.ID] = true
+		}
+		if hide != nil && l.matchesName(hide) {
+			hm = true
+			l.Line = l.unmatchedLines(hide)
+			if len(l.Line) == 0 {
+				hidden[l.ID] = true
+			}
+		}
+	}
+
+	s := make([]*Sample, 0, len(p.Sample))
+	for _, sample := range p.Sample {
+		if focusedAndNotIgnored(sample.Location, focusOrIgnore) {
+			if len(hidden) > 0 {
+				var locs []*Location
+				for _, loc := range sample.Location {
+					if !hidden[loc.ID] {
+						locs = append(locs, loc)
+					}
+				}
+				if len(locs) == 0 {
+					// Remove sample with no locations (by not adding it to s).
+					continue
+				}
+				sample.Location = locs
+			}
+			s = append(s, sample)
+		}
+	}
+	p.Sample = s
+
+	return
+}
+
+// matchesName reports whether the function name or file in the
+// location matches the regular expression.
+func (loc *Location) matchesName(re *regexp.Regexp) bool {
+	for _, ln := range loc.Line {
+		if fn := ln.Function; fn != nil {
+			if re.MatchString(fn.Name) {
+				return true
+			}
+			if re.MatchString(fn.Filename) {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+// unmatchedLines returns the lines in the location that do not match
+// the regular expression.
+func (loc *Location) unmatchedLines(re *regexp.Regexp) []Line {
+	var lines []Line
+	for _, ln := range loc.Line {
+		if fn := ln.Function; fn != nil {
+			if re.MatchString(fn.Name) {
+				continue
+			}
+			if re.MatchString(fn.Filename) {
+				continue
+			}
+		}
+		lines = append(lines, ln)
+	}
+	return lines
+}
+
+// focusedAndNotIgnored looks up a slice of ids against a map of
+// focused/ignored locations. The map only contains locations that are
+// explicitly focused or ignored. Returns whether there is at least
+// one focused location but no ignored locations.
+func focusedAndNotIgnored(locs []*Location, m map[uint64]bool) bool {
+	var f bool
+	for _, loc := range locs {
+		if focus, focusOrIgnore := m[loc.ID]; focusOrIgnore {
+			if focus {
+				// Found focused location. Must keep searching in case there
+				// is an ignored one as well.
+				f = true
+			} else {
+				// Found ignored location. Can return false right away.
+				return false
+			}
+		}
+	}
+	return f
+}
+
+// TagMatch selects tags for filtering
+type TagMatch func(key, val string, nval int64) bool
+
+// FilterSamplesByTag removes all samples from the profile, except
+// those that match focus and do not match the ignore regular
+// expression.
+func (p *Profile) FilterSamplesByTag(focus, ignore TagMatch) (fm, im bool) {
+	samples := make([]*Sample, 0, len(p.Sample))
+	for _, s := range p.Sample {
+		focused, ignored := focusedSample(s, focus, ignore)
+		fm = fm || focused
+		im = im || ignored
+		if focused && !ignored {
+			samples = append(samples, s)
+		}
+	}
+	p.Sample = samples
+	return
+}
+
+// focusedSample checks a sample against focus and ignore regexps.
+// Returns whether the focus/ignore regexps match any tags.
+func focusedSample(s *Sample, focus, ignore TagMatch) (fm, im bool) {
+	fm = focus == nil
+	for key, vals := range s.Label {
+		for _, val := range vals {
+			if ignore != nil && ignore(key, val, 0) {
+				im = true
+			}
+			if !fm && focus(key, val, 0) {
+				fm = true
+			}
+		}
+	}
+	for key, vals := range s.NumLabel {
+		for _, val := range vals {
+			if ignore != nil && ignore(key, "", val) {
+				im = true
+			}
+			if !fm && focus(key, "", val) {
+				fm = true
+			}
+		}
+	}
+	return fm, im
+}
diff --git a/contrib/go/_std_1.20/src/internal/profile/legacy_profile.go b/contrib/go/_std_1.20/src/internal/profile/legacy_profile.go
new file mode 100644
index 0000000000..b102c95904
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/profile/legacy_profile.go
@@ -0,0 +1,1268 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file implements parsers to convert legacy profiles into the
+// profile.proto format.
+
+package profile
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"math"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+var (
+	countStartRE = regexp.MustCompile(`\A(\w+) profile: total \d+\n\z`)
+	countRE      = regexp.MustCompile(`\A(\d+) @(( 0x[0-9a-f]+)+)\n\z`)
+
+	heapHeaderRE = regexp.MustCompile(`heap profile: *(\d+): *(\d+) *\[ *(\d+): *(\d+) *\] *@ *(heap[_a-z0-9]*)/?(\d*)`)
+	heapSampleRE = regexp.MustCompile(`(-?\d+): *(-?\d+) *\[ *(\d+): *(\d+) *] @([ x0-9a-f]*)`)
+
+	contentionSampleRE = regexp.MustCompile(`(\d+) *(\d+) @([ x0-9a-f]*)`)
+
+	hexNumberRE = regexp.MustCompile(`0x[0-9a-f]+`)
+
+	growthHeaderRE = regexp.MustCompile(`heap profile: *(\d+): *(\d+) *\[ *(\d+): *(\d+) *\] @ growthz`)
+
+	fragmentationHeaderRE = regexp.MustCompile(`heap profile: *(\d+): *(\d+) *\[ *(\d+): *(\d+) *\] @ fragmentationz`)
+
+	threadzStartRE = regexp.MustCompile(`--- threadz \d+ ---`)
+	threadStartRE  = regexp.MustCompile(`--- Thread ([[:xdigit:]]+) \(name: (.*)/(\d+)\) stack: ---`)
+
+	procMapsRE = regexp.MustCompile(`([[:xdigit:]]+)-([[:xdigit:]]+)\s+([-rwxp]+)\s+([[:xdigit:]]+)\s+([[:xdigit:]]+):([[:xdigit:]]+)\s+([[:digit:]]+)\s*(\S+)?`)
+
+	briefMapsRE = regexp.MustCompile(`\s*([[:xdigit:]]+)-([[:xdigit:]]+):\s*(\S+)(\s.*@)?([[:xdigit:]]+)?`)
+
+	// LegacyHeapAllocated instructs the heapz parsers to use the
+	// allocated memory stats instead of the default in-use memory. Note
+	// that tcmalloc doesn't provide all allocated memory, only in-use
+	// stats.
+	LegacyHeapAllocated bool
+)
+
+func isSpaceOrComment(line string) bool {
+	trimmed := strings.TrimSpace(line)
+	return len(trimmed) == 0 || trimmed[0] == '#'
+}
+
+// parseGoCount parses a Go count profile (e.g., threadcreate or
+// goroutine) and returns a new Profile.
+func parseGoCount(b []byte) (*Profile, error) {
+	r := bytes.NewBuffer(b)
+
+	var line string
+	var err error
+	for {
+		// Skip past comments and empty lines seeking a real header.
+		line, err = r.ReadString('\n')
+		if err != nil {
+			return nil, err
+		}
+		if !isSpaceOrComment(line) {
+			break
+		}
+	}
+
+	m := countStartRE.FindStringSubmatch(line)
+	if m == nil {
+		return nil, errUnrecognized
+	}
+	profileType := m[1]
+	p := &Profile{
+		PeriodType: &ValueType{Type: profileType, Unit: "count"},
+		Period:     1,
+		SampleType: []*ValueType{{Type: profileType, Unit: "count"}},
+	}
+	locations := make(map[uint64]*Location)
+	for {
+		line, err = r.ReadString('\n')
+		if err != nil {
+			if err == io.EOF {
+				break
+			}
+			return nil, err
+		}
+		if isSpaceOrComment(line) {
+			continue
+		}
+		if strings.HasPrefix(line, "---") {
+			break
+		}
+		m := countRE.FindStringSubmatch(line)
+		if m == nil {
+			return nil, errMalformed
+		}
+		n, err := strconv.ParseInt(m[1], 0, 64)
+		if err != nil {
+			return nil, errMalformed
+		}
+		fields := strings.Fields(m[2])
+		locs := make([]*Location, 0, len(fields))
+		for _, stk := range fields {
+			addr, err := strconv.ParseUint(stk, 0, 64)
+			if err != nil {
+				return nil, errMalformed
+			}
+			// Adjust all frames by -1 to land on the call instruction.
+			addr--
+			loc := locations[addr]
+			if loc == nil {
+				loc = &Location{
+					Address: addr,
+				}
+				locations[addr] = loc
+				p.Location = append(p.Location, loc)
+			}
+			locs = append(locs, loc)
+		}
+		p.Sample = append(p.Sample, &Sample{
+			Location: locs,
+			Value:    []int64{n},
+		})
+	}
+
+	if err = parseAdditionalSections(strings.TrimSpace(line), r, p); err != nil {
+		return nil, err
+	}
+	return p, nil
+}
+
+// remapLocationIDs ensures there is a location for each address
+// referenced by a sample, and remaps the samples to point to the new
+// location ids.
+func (p *Profile) remapLocationIDs() {
+	seen := make(map[*Location]bool, len(p.Location))
+	var locs []*Location
+
+	for _, s := range p.Sample {
+		for _, l := range s.Location {
+			if seen[l] {
+				continue
+			}
+			l.ID = uint64(len(locs) + 1)
+			locs = append(locs, l)
+			seen[l] = true
+		}
+	}
+	p.Location = locs
+}
+
+func (p *Profile) remapFunctionIDs() {
+	seen := make(map[*Function]bool, len(p.Function))
+	var fns []*Function
+
+	for _, l := range p.Location {
+		for _, ln := range l.Line {
+			fn := ln.Function
+			if fn == nil || seen[fn] {
+				continue
+			}
+			fn.ID = uint64(len(fns) + 1)
+			fns = append(fns, fn)
+			seen[fn] = true
+		}
+	}
+	p.Function = fns
+}
+
+// remapMappingIDs matches location addresses with existing mappings
+// and updates them appropriately. This is O(N*M), if this ever shows
+// up as a bottleneck, evaluate sorting the mappings and doing a
+// binary search, which would make it O(N*log(M)).
+func (p *Profile) remapMappingIDs() {
+	if len(p.Mapping) == 0 {
+		return
+	}
+
+	// Some profile handlers will incorrectly set regions for the main
+	// executable if its section is remapped. Fix them through heuristics.
+
+	// Remove the initial mapping if named '/anon_hugepage' and has a
+	// consecutive adjacent mapping.
+	if m := p.Mapping[0]; strings.HasPrefix(m.File, "/anon_hugepage") {
+		if len(p.Mapping) > 1 && m.Limit == p.Mapping[1].Start {
+			p.Mapping = p.Mapping[1:]
+		}
+	}
+
+	for _, l := range p.Location {
+		if a := l.Address; a != 0 {
+			for _, m := range p.Mapping {
+				if m.Start <= a && a < m.Limit {
+					l.Mapping = m
+					break
+				}
+			}
+		}
+	}
+
+	// Reset all mapping IDs.
+	for i, m := range p.Mapping {
+		m.ID = uint64(i + 1)
+	}
+}
+
+var cpuInts = []func([]byte) (uint64, []byte){
+	get32l,
+	get32b,
+	get64l,
+	get64b,
+}
+
+func get32l(b []byte) (uint64, []byte) {
+	if len(b) < 4 {
+		return 0, nil
+	}
+	return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24, b[4:]
+}
+
+func get32b(b []byte) (uint64, []byte) {
+	if len(b) < 4 {
+		return 0, nil
+	}
+	return uint64(b[3]) | uint64(b[2])<<8 | uint64(b[1])<<16 | uint64(b[0])<<24, b[4:]
+}
+
+func get64l(b []byte) (uint64, []byte) {
+	if len(b) < 8 {
+		return 0, nil
+	}
+	return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56, b[8:]
+}
+
+func get64b(b []byte) (uint64, []byte) {
+	if len(b) < 8 {
+		return 0, nil
+	}
+	return uint64(b[7]) | uint64(b[6])<<8 | uint64(b[5])<<16 | uint64(b[4])<<24 | uint64(b[3])<<32 | uint64(b[2])<<40 | uint64(b[1])<<48 | uint64(b[0])<<56, b[8:]
+}
+
+// ParseTracebacks parses a set of tracebacks and returns a newly
+// populated profile. It will accept any text file and generate a
+// Profile out of it with any hex addresses it can identify, including
+// a process map if it can recognize one. Each sample will include a
+// tag "source" with the addresses recognized in string format.
+func ParseTracebacks(b []byte) (*Profile, error) {
+	r := bytes.NewBuffer(b)
+
+	p := &Profile{
+		PeriodType: &ValueType{Type: "trace", Unit: "count"},
+		Period:     1,
+		SampleType: []*ValueType{
+			{Type: "trace", Unit: "count"},
+		},
+	}
+
+	var sources []string
+	var sloc []*Location
+
+	locs := make(map[uint64]*Location)
+	for {
+		l, err := r.ReadString('\n')
+		if err != nil {
+			if err != io.EOF {
+				return nil, err
+			}
+			if l == "" {
+				break
+			}
+		}
+		if sectionTrigger(l) == memoryMapSection {
+			break
+		}
+		if s, addrs := extractHexAddresses(l); len(s) > 0 {
+			for _, addr := range addrs {
+				// Addresses from stack traces point to the next instruction after
+				// each call. Adjust by -1 to land somewhere on the actual call.
+				addr--
+				loc := locs[addr]
+				if locs[addr] == nil {
+					loc = &Location{
+						Address: addr,
+					}
+					p.Location = append(p.Location, loc)
+					locs[addr] = loc
+				}
+				sloc = append(sloc, loc)
+			}
+
+			sources = append(sources, s...)
+		} else {
+			if len(sources) > 0 || len(sloc) > 0 {
+				addTracebackSample(sloc, sources, p)
+				sloc, sources = nil, nil
+			}
+		}
+	}
+
+	// Add final sample to save any leftover data.
+	if len(sources) > 0 || len(sloc) > 0 {
+		addTracebackSample(sloc, sources, p)
+	}
+
+	if err := p.ParseMemoryMap(r); err != nil {
+		return nil, err
+	}
+	return p, nil
+}
+
+func addTracebackSample(l []*Location, s []string, p *Profile) {
+	p.Sample = append(p.Sample,
+		&Sample{
+			Value:    []int64{1},
+			Location: l,
+			Label:    map[string][]string{"source": s},
+		})
+}
+
+// parseCPU parses a profilez legacy profile and returns a newly
+// populated Profile.
+//
+// The general format for profilez samples is a sequence of words in
+// binary format. The first words are a header with the following data:
+//
+//	1st word -- 0
+//	2nd word -- 3
+//	3rd word -- 0 if a c++ application, 1 if a java application.
+//	4th word -- Sampling period (in microseconds).
+//	5th word -- Padding.
+func parseCPU(b []byte) (*Profile, error) {
+	var parse func([]byte) (uint64, []byte)
+	var n1, n2, n3, n4, n5 uint64
+	for _, parse = range cpuInts {
+		var tmp []byte
+		n1, tmp = parse(b)
+		n2, tmp = parse(tmp)
+		n3, tmp = parse(tmp)
+		n4, tmp = parse(tmp)
+		n5, tmp = parse(tmp)
+
+		if tmp != nil && n1 == 0 && n2 == 3 && n3 == 0 && n4 > 0 && n5 == 0 {
+			b = tmp
+			return cpuProfile(b, int64(n4), parse)
+		}
+	}
+	return nil, errUnrecognized
+}
+
+// cpuProfile returns a new Profile from C++ profilez data.
+// b is the profile bytes after the header, period is the profiling
+// period, and parse is a function to parse 8-byte chunks from the
+// profile in its native endianness.
+func cpuProfile(b []byte, period int64, parse func(b []byte) (uint64, []byte)) (*Profile, error) {
+	p := &Profile{
+		Period:     period * 1000,
+		PeriodType: &ValueType{Type: "cpu", Unit: "nanoseconds"},
+		SampleType: []*ValueType{
+			{Type: "samples", Unit: "count"},
+			{Type: "cpu", Unit: "nanoseconds"},
+		},
+	}
+	var err error
+	if b, _, err = parseCPUSamples(b, parse, true, p); err != nil {
+		return nil, err
+	}
+
+	// If all samples have the same second-to-the-bottom frame, it
+	// strongly suggests that it is an uninteresting artifact of
+	// measurement -- a stack frame pushed by the signal handler. The
+	// bottom frame is always correct as it is picked up from the signal
+	// structure, not the stack. Check if this is the case and if so,
+	// remove.
+	if len(p.Sample) > 1 && len(p.Sample[0].Location) > 1 {
+		allSame := true
+		id1 := p.Sample[0].Location[1].Address
+		for _, s := range p.Sample {
+			if len(s.Location) < 2 || id1 != s.Location[1].Address {
+				allSame = false
+				break
+			}
+		}
+		if allSame {
+			for _, s := range p.Sample {
+				s.Location = append(s.Location[:1], s.Location[2:]...)
+			}
+		}
+	}
+
+	if err := p.ParseMemoryMap(bytes.NewBuffer(b)); err != nil {
+		return nil, err
+	}
+	return p, nil
+}
+
+// parseCPUSamples parses a collection of profilez samples from a
+// profile.
+//
+// profilez samples are a repeated sequence of stack frames of the
+// form:
+//
+//	1st word -- The number of times this stack was encountered.
+//	2nd word -- The size of the stack (StackSize).
+//	3rd word -- The first address on the stack.
+//	...
+//	StackSize + 2 -- The last address on the stack
+//
+// The last stack trace is of the form:
+//
+//	1st word -- 0
+//	2nd word -- 1
+//	3rd word -- 0
+//
+// Addresses from stack traces may point to the next instruction after
+// each call. Optionally adjust by -1 to land somewhere on the actual
+// call (except for the leaf, which is not a call).
+func parseCPUSamples(b []byte, parse func(b []byte) (uint64, []byte), adjust bool, p *Profile) ([]byte, map[uint64]*Location, error) {
+	locs := make(map[uint64]*Location)
+	for len(b) > 0 {
+		var count, nstk uint64
+		count, b = parse(b)
+		nstk, b = parse(b)
+		if b == nil || nstk > uint64(len(b)/4) {
+			return nil, nil, errUnrecognized
+		}
+		var sloc []*Location
+		addrs := make([]uint64, nstk)
+		for i := 0; i < int(nstk); i++ {
+			addrs[i], b = parse(b)
+		}
+
+		if count == 0 && nstk == 1 && addrs[0] == 0 {
+			// End of data marker
+			break
+		}
+		for i, addr := range addrs {
+			if adjust && i > 0 {
+				addr--
+			}
+			loc := locs[addr]
+			if loc == nil {
+				loc = &Location{
+					Address: addr,
+				}
+				locs[addr] = loc
+				p.Location = append(p.Location, loc)
+			}
+			sloc = append(sloc, loc)
+		}
+		p.Sample = append(p.Sample,
+			&Sample{
+				Value:    []int64{int64(count), int64(count) * p.Period},
+				Location: sloc,
+			})
+	}
+	// Reached the end without finding the EOD marker.
+	return b, locs, nil
+}
+
+// parseHeap parses a heapz legacy or a growthz profile and
+// returns a newly populated Profile.
+func parseHeap(b []byte) (p *Profile, err error) {
+	r := bytes.NewBuffer(b)
+	l, err := r.ReadString('\n')
+	if err != nil {
+		return nil, errUnrecognized
+	}
+
+	sampling := ""
+
+	if header := heapHeaderRE.FindStringSubmatch(l); header != nil {
+		p = &Profile{
+			SampleType: []*ValueType{
+				{Type: "objects", Unit: "count"},
+				{Type: "space", Unit: "bytes"},
+			},
+			PeriodType: &ValueType{Type: "objects", Unit: "bytes"},
+		}
+
+		var period int64
+		if len(header[6]) > 0 {
+			if period, err = strconv.ParseInt(header[6], 10, 64); err != nil {
+				return nil, errUnrecognized
+			}
+		}
+
+		switch header[5] {
+		case "heapz_v2", "heap_v2":
+			sampling, p.Period = "v2", period
+		case "heapprofile":
+			sampling, p.Period = "", 1
+		case "heap":
+			sampling, p.Period = "v2", period/2
+		default:
+			return nil, errUnrecognized
+		}
+	} else if header = growthHeaderRE.FindStringSubmatch(l); header != nil {
+		p = &Profile{
+			SampleType: []*ValueType{
+				{Type: "objects", Unit: "count"},
+				{Type: "space", Unit: "bytes"},
+			},
+			PeriodType: &ValueType{Type: "heapgrowth", Unit: "count"},
+			Period:     1,
+		}
+	} else if header = fragmentationHeaderRE.FindStringSubmatch(l); header != nil {
+		p = &Profile{
+			SampleType: []*ValueType{
+				{Type: "objects", Unit: "count"},
+				{Type: "space", Unit: "bytes"},
+			},
+			PeriodType: &ValueType{Type: "allocations", Unit: "count"},
+			Period:     1,
+		}
+	} else {
+		return nil, errUnrecognized
+	}
+
+	if LegacyHeapAllocated {
+		for _, st := range p.SampleType {
+			st.Type = "alloc_" + st.Type
+		}
+	} else {
+		for _, st := range p.SampleType {
+			st.Type = "inuse_" + st.Type
+		}
+	}
+
+	locs := make(map[uint64]*Location)
+	for {
+		l, err = r.ReadString('\n')
+		if err != nil {
+			if err != io.EOF {
+				return nil, err
+			}
+
+			if l == "" {
+				break
+			}
+		}
+
+		if isSpaceOrComment(l) {
+			continue
+		}
+		l = strings.TrimSpace(l)
+
+		if sectionTrigger(l) != unrecognizedSection {
+			break
+		}
+
+		value, blocksize, addrs, err := parseHeapSample(l, p.Period, sampling)
+		if err != nil {
+			return nil, err
+		}
+		var sloc []*Location
+		for _, addr := range addrs {
+			// Addresses from stack traces point to the next instruction after
+			// each call. Adjust by -1 to land somewhere on the actual call.
+			addr--
+			loc := locs[addr]
+			if locs[addr] == nil {
+				loc = &Location{
+					Address: addr,
+				}
+				p.Location = append(p.Location, loc)
+				locs[addr] = loc
+			}
+			sloc = append(sloc, loc)
+		}
+
+		p.Sample = append(p.Sample, &Sample{
+			Value:    value,
+			Location: sloc,
+			NumLabel: map[string][]int64{"bytes": {blocksize}},
+		})
+	}
+
+	if err = parseAdditionalSections(l, r, p); err != nil {
+		return nil, err
+	}
+	return p, nil
+}
+
+// parseHeapSample parses a single row from a heap profile into a new Sample.
+func parseHeapSample(line string, rate int64, sampling string) (value []int64, blocksize int64, addrs []uint64, err error) {
+	sampleData := heapSampleRE.FindStringSubmatch(line)
+	if len(sampleData) != 6 {
+		return value, blocksize, addrs, fmt.Errorf("unexpected number of sample values: got %d, want 6", len(sampleData))
+	}
+
+	// Use first two values by default; tcmalloc sampling generates the
+	// same value for both, only the older heap-profile collect separate
+	// stats for in-use and allocated objects.
+	valueIndex := 1
+	if LegacyHeapAllocated {
+		valueIndex = 3
+	}
+
+	var v1, v2 int64
+	if v1, err = strconv.ParseInt(sampleData[valueIndex], 10, 64); err != nil {
+		return value, blocksize, addrs, fmt.Errorf("malformed sample: %s: %v", line, err)
+	}
+	if v2, err = strconv.ParseInt(sampleData[valueIndex+1], 10, 64); err != nil {
+		return value, blocksize, addrs, fmt.Errorf("malformed sample: %s: %v", line, err)
+	}
+
+	if v1 == 0 {
+		if v2 != 0 {
+			return value, blocksize, addrs, fmt.Errorf("allocation count was 0 but allocation bytes was %d", v2)
+		}
+	} else {
+		blocksize = v2 / v1
+		if sampling == "v2" {
+			v1, v2 = scaleHeapSample(v1, v2, rate)
+		}
+	}
+
+	value = []int64{v1, v2}
+	addrs = parseHexAddresses(sampleData[5])
+
+	return value, blocksize, addrs, nil
+}
+
+// extractHexAddresses extracts hex numbers from a string and returns
+// them, together with their numeric value, in a slice.
+func extractHexAddresses(s string) ([]string, []uint64) {
+	hexStrings := hexNumberRE.FindAllString(s, -1)
+	var ids []uint64
+	for _, s := range hexStrings {
+		if id, err := strconv.ParseUint(s, 0, 64); err == nil {
+			ids = append(ids, id)
+		} else {
+			// Do not expect any parsing failures due to the regexp matching.
+			panic("failed to parse hex value:" + s)
+		}
+	}
+	return hexStrings, ids
+}
+
+// parseHexAddresses parses hex numbers from a string and returns them
+// in a slice.
+func parseHexAddresses(s string) []uint64 {
+	_, ids := extractHexAddresses(s)
+	return ids
+}
+
+// scaleHeapSample adjusts the data from a heapz Sample to
+// account for its probability of appearing in the collected
+// data. heapz profiles are a sampling of the memory allocations
+// requests in a program. We estimate the unsampled value by dividing
+// each collected sample by its probability of appearing in the
+// profile. heapz v2 profiles rely on a poisson process to determine
+// which samples to collect, based on the desired average collection
+// rate R. The probability of a sample of size S to appear in that
+// profile is 1-exp(-S/R).
+func scaleHeapSample(count, size, rate int64) (int64, int64) {
+	if count == 0 || size == 0 {
+		return 0, 0
+	}
+
+	if rate <= 1 {
+		// if rate==1 all samples were collected so no adjustment is needed.
+		// if rate<1 treat as unknown and skip scaling.
+		return count, size
+	}
+
+	avgSize := float64(size) / float64(count)
+	scale := 1 / (1 - math.Exp(-avgSize/float64(rate)))
+
+	return int64(float64(count) * scale), int64(float64(size) * scale)
+}
+
+// parseContention parses a mutex or contention profile. There are 2 cases:
+// "--- contentionz " for legacy C++ profiles (and backwards compatibility)
+// "--- mutex:" or "--- contention:" for profiles generated by the Go runtime.
+// This code converts the text output from runtime into a *Profile. (In the future
+// the runtime might write a serialized Profile directly making this unnecessary.)
+func parseContention(b []byte) (*Profile, error) {
+	r := bytes.NewBuffer(b)
+	var l string
+	var err error
+	for {
+		// Skip past comments and empty lines seeking a real header.
+		l, err = r.ReadString('\n')
+		if err != nil {
+			return nil, err
+		}
+		if !isSpaceOrComment(l) {
+			break
+		}
+	}
+
+	if strings.HasPrefix(l, "--- contentionz ") {
+		return parseCppContention(r)
+	} else if strings.HasPrefix(l, "--- mutex:") {
+		return parseCppContention(r)
+	} else if strings.HasPrefix(l, "--- contention:") {
+		return parseCppContention(r)
+	}
+	return nil, errUnrecognized
+}
+
+// parseCppContention parses the output from synchronization_profiling.cc
+// for backward compatibility, and the compatible (non-debug) block profile
+// output from the Go runtime.
+func parseCppContention(r *bytes.Buffer) (*Profile, error) {
+	p := &Profile{
+		PeriodType: &ValueType{Type: "contentions", Unit: "count"},
+		Period:     1,
+		SampleType: []*ValueType{
+			{Type: "contentions", Unit: "count"},
+			{Type: "delay", Unit: "nanoseconds"},
+		},
+	}
+
+	var cpuHz int64
+	var l string
+	var err error
+	// Parse text of the form "attribute = value" before the samples.
+	const delimiter = '='
+	for {
+		l, err = r.ReadString('\n')
+		if err != nil {
+			if err != io.EOF {
+				return nil, err
+			}
+
+			if l == "" {
+				break
+			}
+		}
+		if isSpaceOrComment(l) {
+			continue
+		}
+
+		if l = strings.TrimSpace(l); l == "" {
+			continue
+		}
+
+		if strings.HasPrefix(l, "---") {
+			break
+		}
+
+		index := strings.IndexByte(l, delimiter)
+		if index < 0 {
+			break
+		}
+		key := l[:index]
+		val := l[index+1:]
+
+		key, val = strings.TrimSpace(key), strings.TrimSpace(val)
+		var err error
+		switch key {
+		case "cycles/second":
+			if cpuHz, err = strconv.ParseInt(val, 0, 64); err != nil {
+				return nil, errUnrecognized
+			}
+		case "sampling period":
+			if p.Period, err = strconv.ParseInt(val, 0, 64); err != nil {
+				return nil, errUnrecognized
+			}
+		case "ms since reset":
+			ms, err := strconv.ParseInt(val, 0, 64)
+			if err != nil {
+				return nil, errUnrecognized
+			}
+			p.DurationNanos = ms * 1000 * 1000
+		case "format":
+			// CPP contentionz profiles don't have format.
+			return nil, errUnrecognized
+		case "resolution":
+			// CPP contentionz profiles don't have resolution.
+			return nil, errUnrecognized
+		case "discarded samples":
+		default:
+			return nil, errUnrecognized
+		}
+	}
+
+	locs := make(map[uint64]*Location)
+	for {
+		if !isSpaceOrComment(l) {
+			if l = strings.TrimSpace(l); strings.HasPrefix(l, "---") {
+				break
+			}
+			value, addrs, err := parseContentionSample(l, p.Period, cpuHz)
+			if err != nil {
+				return nil, err
+			}
+			var sloc []*Location
+			for _, addr := range addrs {
+				// Addresses from stack traces point to the next instruction after
+				// each call. Adjust by -1 to land somewhere on the actual call.
+				addr--
+				loc := locs[addr]
+				if locs[addr] == nil {
+					loc = &Location{
+						Address: addr,
+					}
+					p.Location = append(p.Location, loc)
+					locs[addr] = loc
+				}
+				sloc = append(sloc, loc)
+			}
+			p.Sample = append(p.Sample, &Sample{
+				Value:    value,
+				Location: sloc,
+			})
+		}
+
+		if l, err = r.ReadString('\n'); err != nil {
+			if err != io.EOF {
+				return nil, err
+			}
+			if l == "" {
+				break
+			}
+		}
+	}
+
+	if err = parseAdditionalSections(l, r, p); err != nil {
+		return nil, err
+	}
+
+	return p, nil
+}
+
+// parseContentionSample parses a single row from a contention profile
+// into a new Sample.
+func parseContentionSample(line string, period, cpuHz int64) (value []int64, addrs []uint64, err error) {
+	sampleData := contentionSampleRE.FindStringSubmatch(line)
+	if sampleData == nil {
+		return value, addrs, errUnrecognized
+	}
+
+	v1, err := strconv.ParseInt(sampleData[1], 10, 64)
+	if err != nil {
+		return value, addrs, fmt.Errorf("malformed sample: %s: %v", line, err)
+	}
+	v2, err := strconv.ParseInt(sampleData[2], 10, 64)
+	if err != nil {
+		return value, addrs, fmt.Errorf("malformed sample: %s: %v", line, err)
+	}
+
+	// Unsample values if period and cpuHz are available.
+	// - Delays are scaled to cycles and then to nanoseconds.
+	// - Contentions are scaled to cycles.
+	if period > 0 {
+		if cpuHz > 0 {
+			cpuGHz := float64(cpuHz) / 1e9
+			v1 = int64(float64(v1) * float64(period) / cpuGHz)
+		}
+		v2 = v2 * period
+	}
+
+	value = []int64{v2, v1}
+	addrs = parseHexAddresses(sampleData[3])
+
+	return value, addrs, nil
+}
+
+// parseThread parses a Threadz profile and returns a new Profile.
+func parseThread(b []byte) (*Profile, error) {
+	r := bytes.NewBuffer(b)
+
+	var line string
+	var err error
+	for {
+		// Skip past comments and empty lines seeking a real header.
+		line, err = r.ReadString('\n')
+		if err != nil {
+			return nil, err
+		}
+		if !isSpaceOrComment(line) {
+			break
+		}
+	}
+
+	if m := threadzStartRE.FindStringSubmatch(line); m != nil {
+		// Advance over initial comments until first stack trace.
+		for {
+			line, err = r.ReadString('\n')
+			if err != nil {
+				if err != io.EOF {
+					return nil, err
+				}
+
+				if line == "" {
+					break
+				}
+			}
+			if sectionTrigger(line) != unrecognizedSection || line[0] == '-' {
+				break
+			}
+		}
+	} else if t := threadStartRE.FindStringSubmatch(line); len(t) != 4 {
+		return nil, errUnrecognized
+	}
+
+	p := &Profile{
+		SampleType: []*ValueType{{Type: "thread", Unit: "count"}},
+		PeriodType: &ValueType{Type: "thread", Unit: "count"},
+		Period:     1,
+	}
+
+	locs := make(map[uint64]*Location)
+	// Recognize each thread and populate profile samples.
+	for sectionTrigger(line) == unrecognizedSection {
+		if strings.HasPrefix(line, "---- no stack trace for") {
+			line = ""
+			break
+		}
+		if t := threadStartRE.FindStringSubmatch(line); len(t) != 4 {
+			return nil, errUnrecognized
+		}
+
+		var addrs []uint64
+		line, addrs, err = parseThreadSample(r)
+		if err != nil {
+			return nil, errUnrecognized
+		}
+		if len(addrs) == 0 {
+			// We got a --same as previous threads--. Bump counters.
+			if len(p.Sample) > 0 {
+				s := p.Sample[len(p.Sample)-1]
+				s.Value[0]++
+			}
+			continue
+		}
+
+		var sloc []*Location
+		for _, addr := range addrs {
+			// Addresses from stack traces point to the next instruction after
+			// each call. Adjust by -1 to land somewhere on the actual call.
+			addr--
+			loc := locs[addr]
+			if locs[addr] == nil {
+				loc = &Location{
+					Address: addr,
+				}
+				p.Location = append(p.Location, loc)
+				locs[addr] = loc
+			}
+			sloc = append(sloc, loc)
+		}
+
+		p.Sample = append(p.Sample, &Sample{
+			Value:    []int64{1},
+			Location: sloc,
+		})
+	}
+
+	if err = parseAdditionalSections(line, r, p); err != nil {
+		return nil, err
+	}
+
+	return p, nil
+}
+
+// parseThreadSample parses a symbolized or unsymbolized stack trace.
+// Returns the first line after the traceback, the sample (or nil if
+// it hits a 'same-as-previous' marker) and an error.
+func parseThreadSample(b *bytes.Buffer) (nextl string, addrs []uint64, err error) {
+	var l string
+	sameAsPrevious := false
+	for {
+		if l, err = b.ReadString('\n'); err != nil {
+			if err != io.EOF {
+				return "", nil, err
+			}
+			if l == "" {
+				break
+			}
+		}
+		if l = strings.TrimSpace(l); l == "" {
+			continue
+		}
+
+		if strings.HasPrefix(l, "---") {
+			break
+		}
+		if strings.Contains(l, "same as previous thread") {
+			sameAsPrevious = true
+			continue
+		}
+
+		addrs = append(addrs, parseHexAddresses(l)...)
+	}
+
+	if sameAsPrevious {
+		return l, nil, nil
+	}
+	return l, addrs, nil
+}
+
+// parseAdditionalSections parses any additional sections in the
+// profile, ignoring any unrecognized sections.
+func parseAdditionalSections(l string, b *bytes.Buffer, p *Profile) (err error) {
+	for {
+		if sectionTrigger(l) == memoryMapSection {
+			break
+		}
+		// Ignore any unrecognized sections.
+		if l, err := b.ReadString('\n'); err != nil {
+			if err != io.EOF {
+				return err
+			}
+			if l == "" {
+				break
+			}
+		}
+	}
+	return p.ParseMemoryMap(b)
+}
+
+// ParseMemoryMap parses a memory map in the format of
+// /proc/self/maps, and overrides the mappings in the current profile.
+// It renumbers the samples and locations in the profile correspondingly.
+func (p *Profile) ParseMemoryMap(rd io.Reader) error {
+	b := bufio.NewReader(rd)
+
+	var attrs []string
+	var r *strings.Replacer
+	const delimiter = '='
+	for {
+		l, err := b.ReadString('\n')
+		if err != nil {
+			if err != io.EOF {
+				return err
+			}
+			if l == "" {
+				break
+			}
+		}
+		if l = strings.TrimSpace(l); l == "" {
+			continue
+		}
+
+		if r != nil {
+			l = r.Replace(l)
+		}
+		m, err := parseMappingEntry(l)
+		if err != nil {
+			if err == errUnrecognized {
+				// Recognize assignments of the form: attr=value, and replace
+				// $attr with value on subsequent mappings.
+				idx := strings.IndexByte(l, delimiter)
+				if idx >= 0 {
+					attr := l[:idx]
+					value := l[idx+1:]
+					attrs = append(attrs, "$"+strings.TrimSpace(attr), strings.TrimSpace(value))
+					r = strings.NewReplacer(attrs...)
+				}
+				// Ignore any unrecognized entries
+				continue
+			}
+			return err
+		}
+		if m == nil || (m.File == "" && len(p.Mapping) != 0) {
+			// In some cases the first entry may include the address range
+			// but not the name of the file. It should be followed by
+			// another entry with the name.
+			continue
+		}
+		if len(p.Mapping) == 1 && p.Mapping[0].File == "" {
+			// Update the name if this is the entry following that empty one.
+			p.Mapping[0].File = m.File
+			continue
+		}
+		p.Mapping = append(p.Mapping, m)
+	}
+	p.remapLocationIDs()
+	p.remapFunctionIDs()
+	p.remapMappingIDs()
+	return nil
+}
+
+func parseMappingEntry(l string) (*Mapping, error) {
+	mapping := &Mapping{}
+	var err error
+	if me := procMapsRE.FindStringSubmatch(l); len(me) == 9 {
+		if !strings.Contains(me[3], "x") {
+			// Skip non-executable entries.
+			return nil, nil
+		}
+		if mapping.Start, err = strconv.ParseUint(me[1], 16, 64); err != nil {
+			return nil, errUnrecognized
+		}
+		if mapping.Limit, err = strconv.ParseUint(me[2], 16, 64); err != nil {
+			return nil, errUnrecognized
+		}
+		if me[4] != "" {
+			if mapping.Offset, err = strconv.ParseUint(me[4], 16, 64); err != nil {
+				return nil, errUnrecognized
+			}
+		}
+		mapping.File = me[8]
+		return mapping, nil
+	}
+
+	if me := briefMapsRE.FindStringSubmatch(l); len(me) == 6 {
+		if mapping.Start, err = strconv.ParseUint(me[1], 16, 64); err != nil {
+			return nil, errUnrecognized
+		}
+		if mapping.Limit, err = strconv.ParseUint(me[2], 16, 64); err != nil {
+			return nil, errUnrecognized
+		}
+		mapping.File = me[3]
+		if me[5] != "" {
+			if mapping.Offset, err = strconv.ParseUint(me[5], 16, 64); err != nil {
+				return nil, errUnrecognized
+			}
+		}
+		return mapping, nil
+	}
+
+	return nil, errUnrecognized
+}
+
+type sectionType int
+
+const (
+	unrecognizedSection sectionType = iota
+	memoryMapSection
+)
+
+var memoryMapTriggers = []string{
+	"--- Memory map: ---",
+	"MAPPED_LIBRARIES:",
+}
+
+func sectionTrigger(line string) sectionType {
+	for _, trigger := range memoryMapTriggers {
+		if strings.Contains(line, trigger) {
+			return memoryMapSection
+		}
+	}
+	return unrecognizedSection
+}
+
+func (p *Profile) addLegacyFrameInfo() {
+	switch {
+	case isProfileType(p, heapzSampleTypes) ||
+		isProfileType(p, heapzInUseSampleTypes) ||
+		isProfileType(p, heapzAllocSampleTypes):
+		p.DropFrames, p.KeepFrames = allocRxStr, allocSkipRxStr
+	case isProfileType(p, contentionzSampleTypes):
+		p.DropFrames, p.KeepFrames = lockRxStr, ""
+	default:
+		p.DropFrames, p.KeepFrames = cpuProfilerRxStr, ""
+	}
+}
+
+var heapzSampleTypes = []string{"allocations", "size"} // early Go pprof profiles
+var heapzInUseSampleTypes = []string{"inuse_objects", "inuse_space"}
+var heapzAllocSampleTypes = []string{"alloc_objects", "alloc_space"}
+var contentionzSampleTypes = []string{"contentions", "delay"}
+
+func isProfileType(p *Profile, t []string) bool {
+	st := p.SampleType
+	if len(st) != len(t) {
+		return false
+	}
+
+	for i := range st {
+		if st[i].Type != t[i] {
+			return false
+		}
+	}
+	return true
+}
+
+var allocRxStr = strings.Join([]string{
+	// POSIX entry points.
+	`calloc`,
+	`cfree`,
+	`malloc`,
+	`free`,
+	`memalign`,
+	`do_memalign`,
+	`(__)?posix_memalign`,
+	`pvalloc`,
+	`valloc`,
+	`realloc`,
+
+	// TC malloc.
+	`tcmalloc::.*`,
+	`tc_calloc`,
+	`tc_cfree`,
+	`tc_malloc`,
+	`tc_free`,
+	`tc_memalign`,
+	`tc_posix_memalign`,
+	`tc_pvalloc`,
+	`tc_valloc`,
+	`tc_realloc`,
+	`tc_new`,
+	`tc_delete`,
+	`tc_newarray`,
+	`tc_deletearray`,
+	`tc_new_nothrow`,
+	`tc_newarray_nothrow`,
+
+	// Memory-allocation routines on OS X.
+	`malloc_zone_malloc`,
+	`malloc_zone_calloc`,
+	`malloc_zone_valloc`,
+	`malloc_zone_realloc`,
+	`malloc_zone_memalign`,
+	`malloc_zone_free`,
+
+	// Go runtime
+	`runtime\..*`,
+
+	// Other misc. memory allocation routines
+	`BaseArena::.*`,
+	`(::)?do_malloc_no_errno`,
+	`(::)?do_malloc_pages`,
+	`(::)?do_malloc`,
+	`DoSampledAllocation`,
+	`MallocedMemBlock::MallocedMemBlock`,
+	`_M_allocate`,
+	`__builtin_(vec_)?delete`,
+	`__builtin_(vec_)?new`,
+	`__gnu_cxx::new_allocator::allocate`,
+	`__libc_malloc`,
+	`__malloc_alloc_template::allocate`,
+	`allocate`,
+	`cpp_alloc`,
+	`operator new(\[\])?`,
+	`simple_alloc::allocate`,
+}, `|`)
+
+var allocSkipRxStr = strings.Join([]string{
+	// Preserve Go runtime frames that appear in the middle/bottom of
+	// the stack.
+	`runtime\.panic`,
+	`runtime\.reflectcall`,
+	`runtime\.call[0-9]*`,
+}, `|`)
+
+var cpuProfilerRxStr = strings.Join([]string{
+	`ProfileData::Add`,
+	`ProfileData::prof_handler`,
+	`CpuProfiler::prof_handler`,
+	`__pthread_sighandler`,
+	`__restore`,
+}, `|`)
+
+var lockRxStr = strings.Join([]string{
+	`RecordLockProfileData`,
+	`(base::)?RecordLockProfileData.*`,
+	`(base::)?SubmitMutexProfileData.*`,
+	`(base::)?SubmitSpinLockProfileData.*`,
+	`(Mutex::)?AwaitCommon.*`,
+	`(Mutex::)?Unlock.*`,
+	`(Mutex::)?UnlockSlow.*`,
+	`(Mutex::)?ReaderUnlock.*`,
+	`(MutexLock::)?~MutexLock.*`,
+	`(SpinLock::)?Unlock.*`,
+	`(SpinLock::)?SlowUnlock.*`,
+	`(SpinLockHolder::)?~SpinLockHolder.*`,
+}, `|`)
diff --git a/contrib/go/_std_1.20/src/internal/profile/merge.go b/contrib/go/_std_1.20/src/internal/profile/merge.go
new file mode 100644
index 0000000000..3ea7d4cf42
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/profile/merge.go
@@ -0,0 +1,461 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package profile
+
+import (
+	"fmt"
+	"sort"
+	"strconv"
+	"strings"
+)
+
+// Merge merges all the profiles in profs into a single Profile.
+// Returns a new profile independent of the input profiles. The merged
+// profile is compacted to eliminate unused samples, locations,
+// functions and mappings. Profiles must have identical profile sample
+// and period types or the merge will fail. profile.Period of the
+// resulting profile will be the maximum of all profiles, and
+// profile.TimeNanos will be the earliest nonzero one.
+func Merge(srcs []*Profile) (*Profile, error) {
+	if len(srcs) == 0 {
+		return nil, fmt.Errorf("no profiles to merge")
+	}
+	p, err := combineHeaders(srcs)
+	if err != nil {
+		return nil, err
+	}
+
+	pm := &profileMerger{
+		p:         p,
+		samples:   make(map[sampleKey]*Sample, len(srcs[0].Sample)),
+		locations: make(map[locationKey]*Location, len(srcs[0].Location)),
+		functions: make(map[functionKey]*Function, len(srcs[0].Function)),
+		mappings:  make(map[mappingKey]*Mapping, len(srcs[0].Mapping)),
+	}
+
+	for _, src := range srcs {
+		// Clear the profile-specific hash tables
+		pm.locationsByID = make(map[uint64]*Location, len(src.Location))
+		pm.functionsByID = make(map[uint64]*Function, len(src.Function))
+		pm.mappingsByID = make(map[uint64]mapInfo, len(src.Mapping))
+
+		if len(pm.mappings) == 0 && len(src.Mapping) > 0 {
+			// The Mapping list has the property that the first mapping
+			// represents the main binary. Take the first Mapping we see,
+			// otherwise the operations below will add mappings in an
+			// arbitrary order.
+			pm.mapMapping(src.Mapping[0])
+		}
+
+		for _, s := range src.Sample {
+			if !isZeroSample(s) {
+				pm.mapSample(s)
+			}
+		}
+	}
+
+	for _, s := range p.Sample {
+		if isZeroSample(s) {
+			// If there are any zero samples, re-merge the profile to GC
+			// them.
+			return Merge([]*Profile{p})
+		}
+	}
+
+	return p, nil
+}
+
+// Normalize normalizes the source profile by multiplying each value in profile by the
+// ratio of the sum of the base profile's values of that sample type to the sum of the
+// source profile's value of that sample type.
+func (p *Profile) Normalize(pb *Profile) error {
+
+	if err := p.compatible(pb); err != nil {
+		return err
+	}
+
+	baseVals := make([]int64, len(p.SampleType))
+	for _, s := range pb.Sample {
+		for i, v := range s.Value {
+			baseVals[i] += v
+		}
+	}
+
+	srcVals := make([]int64, len(p.SampleType))
+	for _, s := range p.Sample {
+		for i, v := range s.Value {
+			srcVals[i] += v
+		}
+	}
+
+	normScale := make([]float64, len(baseVals))
+	for i := range baseVals {
+		if srcVals[i] == 0 {
+			normScale[i] = 0.0
+		} else {
+			normScale[i] = float64(baseVals[i]) / float64(srcVals[i])
+		}
+	}
+	p.ScaleN(normScale)
+	return nil
+}
+
+func isZeroSample(s *Sample) bool {
+	for _, v := range s.Value {
+		if v != 0 {
+			return false
+		}
+	}
+	return true
+}
+
+type profileMerger struct {
+	p *Profile
+
+	// Memoization tables within a profile.
+	locationsByID map[uint64]*Location
+	functionsByID map[uint64]*Function
+	mappingsByID  map[uint64]mapInfo
+
+	// Memoization tables for profile entities.
+	samples   map[sampleKey]*Sample
+	locations map[locationKey]*Location
+	functions map[functionKey]*Function
+	mappings  map[mappingKey]*Mapping
+}
+
+type mapInfo struct {
+	m      *Mapping
+	offset int64
+}
+
+func (pm *profileMerger) mapSample(src *Sample) *Sample {
+	s := &Sample{
+		Location: make([]*Location, len(src.Location)),
+		Value:    make([]int64, len(src.Value)),
+		Label:    make(map[string][]string, len(src.Label)),
+		NumLabel: make(map[string][]int64, len(src.NumLabel)),
+		NumUnit:  make(map[string][]string, len(src.NumLabel)),
+	}
+	for i, l := range src.Location {
+		s.Location[i] = pm.mapLocation(l)
+	}
+	for k, v := range src.Label {
+		vv := make([]string, len(v))
+		copy(vv, v)
+		s.Label[k] = vv
+	}
+	for k, v := range src.NumLabel {
+		u := src.NumUnit[k]
+		vv := make([]int64, len(v))
+		uu := make([]string, len(u))
+		copy(vv, v)
+		copy(uu, u)
+		s.NumLabel[k] = vv
+		s.NumUnit[k] = uu
+	}
+	// Check memoization table. Must be done on the remapped location to
+	// account for the remapped mapping. Add current values to the
+	// existing sample.
+	k := s.key()
+	if ss, ok := pm.samples[k]; ok {
+		for i, v := range src.Value {
+			ss.Value[i] += v
+		}
+		return ss
+	}
+	copy(s.Value, src.Value)
+	pm.samples[k] = s
+	pm.p.Sample = append(pm.p.Sample, s)
+	return s
+}
+
+// key generates sampleKey to be used as a key for maps.
+func (sample *Sample) key() sampleKey {
+	ids := make([]string, len(sample.Location))
+	for i, l := range sample.Location {
+		ids[i] = strconv.FormatUint(l.ID, 16)
+	}
+
+	labels := make([]string, 0, len(sample.Label))
+	for k, v := range sample.Label {
+		labels = append(labels, fmt.Sprintf("%q%q", k, v))
+	}
+	sort.Strings(labels)
+
+	numlabels := make([]string, 0, len(sample.NumLabel))
+	for k, v := range sample.NumLabel {
+		numlabels = append(numlabels, fmt.Sprintf("%q%x%x", k, v, sample.NumUnit[k]))
+	}
+	sort.Strings(numlabels)
+
+	return sampleKey{
+		strings.Join(ids, "|"),
+		strings.Join(labels, ""),
+		strings.Join(numlabels, ""),
+	}
+}
+
+type sampleKey struct {
+	locations string
+	labels    string
+	numlabels string
+}
+
+func (pm *profileMerger) mapLocation(src *Location) *Location {
+	if src == nil {
+		return nil
+	}
+
+	if l, ok := pm.locationsByID[src.ID]; ok {
+		pm.locationsByID[src.ID] = l
+		return l
+	}
+
+	mi := pm.mapMapping(src.Mapping)
+	l := &Location{
+		ID:       uint64(len(pm.p.Location) + 1),
+		Mapping:  mi.m,
+		Address:  uint64(int64(src.Address) + mi.offset),
+		Line:     make([]Line, len(src.Line)),
+		IsFolded: src.IsFolded,
+	}
+	for i, ln := range src.Line {
+		l.Line[i] = pm.mapLine(ln)
+	}
+	// Check memoization table. Must be done on the remapped location to
+	// account for the remapped mapping ID.
+	k := l.key()
+	if ll, ok := pm.locations[k]; ok {
+		pm.locationsByID[src.ID] = ll
+		return ll
+	}
+	pm.locationsByID[src.ID] = l
+	pm.locations[k] = l
+	pm.p.Location = append(pm.p.Location, l)
+	return l
+}
+
+// key generates locationKey to be used as a key for maps.
+func (l *Location) key() locationKey {
+	key := locationKey{
+		addr:     l.Address,
+		isFolded: l.IsFolded,
+	}
+	if l.Mapping != nil {
+		// Normalizes address to handle address space randomization.
+		key.addr -= l.Mapping.Start
+		key.mappingID = l.Mapping.ID
+	}
+	lines := make([]string, len(l.Line)*2)
+	for i, line := range l.Line {
+		if line.Function != nil {
+			lines[i*2] = strconv.FormatUint(line.Function.ID, 16)
+		}
+		lines[i*2+1] = strconv.FormatInt(line.Line, 16)
+	}
+	key.lines = strings.Join(lines, "|")
+	return key
+}
+
+type locationKey struct {
+	addr, mappingID uint64
+	lines           string
+	isFolded        bool
+}
+
+func (pm *profileMerger) mapMapping(src *Mapping) mapInfo {
+	if src == nil {
+		return mapInfo{}
+	}
+
+	if mi, ok := pm.mappingsByID[src.ID]; ok {
+		return mi
+	}
+
+	// Check memoization tables.
+	mk := src.key()
+	if m, ok := pm.mappings[mk]; ok {
+		mi := mapInfo{m, int64(m.Start) - int64(src.Start)}
+		pm.mappingsByID[src.ID] = mi
+		return mi
+	}
+	m := &Mapping{
+		ID:              uint64(len(pm.p.Mapping) + 1),
+		Start:           src.Start,
+		Limit:           src.Limit,
+		Offset:          src.Offset,
+		File:            src.File,
+		BuildID:         src.BuildID,
+		HasFunctions:    src.HasFunctions,
+		HasFilenames:    src.HasFilenames,
+		HasLineNumbers:  src.HasLineNumbers,
+		HasInlineFrames: src.HasInlineFrames,
+	}
+	pm.p.Mapping = append(pm.p.Mapping, m)
+
+	// Update memoization tables.
+	pm.mappings[mk] = m
+	mi := mapInfo{m, 0}
+	pm.mappingsByID[src.ID] = mi
+	return mi
+}
+
+// key generates encoded strings of Mapping to be used as a key for
+// maps.
+func (m *Mapping) key() mappingKey {
+	// Normalize addresses to handle address space randomization.
+	// Round up to next 4K boundary to avoid minor discrepancies.
+	const mapsizeRounding = 0x1000
+
+	size := m.Limit - m.Start
+	size = size + mapsizeRounding - 1
+	size = size - (size % mapsizeRounding)
+	key := mappingKey{
+		size:   size,
+		offset: m.Offset,
+	}
+
+	switch {
+	case m.BuildID != "":
+		key.buildIDOrFile = m.BuildID
+	case m.File != "":
+		key.buildIDOrFile = m.File
+	default:
+		// A mapping containing neither build ID nor file name is a fake mapping. A
+		// key with empty buildIDOrFile is used for fake mappings so that they are
+		// treated as the same mapping during merging.
+	}
+	return key
+}
+
+type mappingKey struct {
+	size, offset  uint64
+	buildIDOrFile string
+}
+
+func (pm *profileMerger) mapLine(src Line) Line {
+	ln := Line{
+		Function: pm.mapFunction(src.Function),
+		Line:     src.Line,
+	}
+	return ln
+}
+
+func (pm *profileMerger) mapFunction(src *Function) *Function {
+	if src == nil {
+		return nil
+	}
+	if f, ok := pm.functionsByID[src.ID]; ok {
+		return f
+	}
+	k := src.key()
+	if f, ok := pm.functions[k]; ok {
+		pm.functionsByID[src.ID] = f
+		return f
+	}
+	f := &Function{
+		ID:         uint64(len(pm.p.Function) + 1),
+		Name:       src.Name,
+		SystemName: src.SystemName,
+		Filename:   src.Filename,
+		StartLine:  src.StartLine,
+	}
+	pm.functions[k] = f
+	pm.functionsByID[src.ID] = f
+	pm.p.Function = append(pm.p.Function, f)
+	return f
+}
+
+// key generates a struct to be used as a key for maps.
+func (f *Function) key() functionKey {
+	return functionKey{
+		f.StartLine,
+		f.Name,
+		f.SystemName,
+		f.Filename,
+	}
+}
+
+type functionKey struct {
+	startLine                  int64
+	name, systemName, fileName string
+}
+
+// combineHeaders checks that all profiles can be merged and returns
+// their combined profile.
+func combineHeaders(srcs []*Profile) (*Profile, error) {
+	for _, s := range srcs[1:] {
+		if err := srcs[0].compatible(s); err != nil {
+			return nil, err
+		}
+	}
+
+	var timeNanos, durationNanos, period int64
+	var comments []string
+	seenComments := map[string]bool{}
+	var defaultSampleType string
+	for _, s := range srcs {
+		if timeNanos == 0 || s.TimeNanos < timeNanos {
+			timeNanos = s.TimeNanos
+		}
+		durationNanos += s.DurationNanos
+		if period == 0 || period < s.Period {
+			period = s.Period
+		}
+		for _, c := range s.Comments {
+			if seen := seenComments[c]; !seen {
+				comments = append(comments, c)
+				seenComments[c] = true
+			}
+		}
+		if defaultSampleType == "" {
+			defaultSampleType = s.DefaultSampleType
+		}
+	}
+
+	p := &Profile{
+		SampleType: make([]*ValueType, len(srcs[0].SampleType)),
+
+		DropFrames: srcs[0].DropFrames,
+		KeepFrames: srcs[0].KeepFrames,
+
+		TimeNanos:     timeNanos,
+		DurationNanos: durationNanos,
+		PeriodType:    srcs[0].PeriodType,
+		Period:        period,
+
+		Comments:          comments,
+		DefaultSampleType: defaultSampleType,
+	}
+	copy(p.SampleType, srcs[0].SampleType)
+	return p, nil
+}
+
+// compatible determines if two profiles can be compared/merged.
+// returns nil if the profiles are compatible; otherwise an error with
+// details on the incompatibility.
+func (p *Profile) compatible(pb *Profile) error {
+	if !equalValueType(p.PeriodType, pb.PeriodType) {
+		return fmt.Errorf("incompatible period types %v and %v", p.PeriodType, pb.PeriodType)
+	}
+
+	if len(p.SampleType) != len(pb.SampleType) {
+		return fmt.Errorf("incompatible sample types %v and %v", p.SampleType, pb.SampleType)
+	}
+
+	for i := range p.SampleType {
+		if !equalValueType(p.SampleType[i], pb.SampleType[i]) {
+			return fmt.Errorf("incompatible sample types %v and %v", p.SampleType, pb.SampleType)
+		}
+	}
+	return nil
+}
+
+// equalValueType returns true if the two value types are semantically
+// equal. It ignores the internal fields used during encode/decode.
+func equalValueType(st1, st2 *ValueType) bool {
+	return st1.Type == st2.Type && st1.Unit == st2.Unit
+}
diff --git a/contrib/go/_std_1.20/src/internal/profile/profile.go b/contrib/go/_std_1.20/src/internal/profile/profile.go
new file mode 100644
index 0000000000..29568aa4b5
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/profile/profile.go
@@ -0,0 +1,613 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package profile provides a representation of
+// github.com/google/pprof/proto/profile.proto and
+// methods to encode/decode/merge profiles in this format.
+package profile
+
+import (
+	"bytes"
+	"compress/gzip"
+	"fmt"
+	"io"
+	"regexp"
+	"strings"
+	"time"
+)
+
+// Profile is an in-memory representation of profile.proto.
+type Profile struct {
+	SampleType        []*ValueType
+	DefaultSampleType string
+	Sample            []*Sample
+	Mapping           []*Mapping
+	Location          []*Location
+	Function          []*Function
+	Comments          []string
+
+	DropFrames string
+	KeepFrames string
+
+	TimeNanos     int64
+	DurationNanos int64
+	PeriodType    *ValueType
+	Period        int64
+
+	commentX           []int64
+	dropFramesX        int64
+	keepFramesX        int64
+	stringTable        []string
+	defaultSampleTypeX int64
+}
+
+// ValueType corresponds to Profile.ValueType
+type ValueType struct {
+	Type string // cpu, wall, inuse_space, etc
+	Unit string // seconds, nanoseconds, bytes, etc
+
+	typeX int64
+	unitX int64
+}
+
+// Sample corresponds to Profile.Sample
+type Sample struct {
+	Location []*Location
+	Value    []int64
+	Label    map[string][]string
+	NumLabel map[string][]int64
+	NumUnit  map[string][]string
+
+	locationIDX []uint64
+	labelX      []Label
+}
+
+// Label corresponds to Profile.Label
+type Label struct {
+	keyX int64
+	// Exactly one of the two following values must be set
+	strX int64
+	numX int64 // Integer value for this label
+}
+
+// Mapping corresponds to Profile.Mapping
+type Mapping struct {
+	ID              uint64
+	Start           uint64
+	Limit           uint64
+	Offset          uint64
+	File            string
+	BuildID         string
+	HasFunctions    bool
+	HasFilenames    bool
+	HasLineNumbers  bool
+	HasInlineFrames bool
+
+	fileX    int64
+	buildIDX int64
+}
+
+// Location corresponds to Profile.Location
+type Location struct {
+	ID       uint64
+	Mapping  *Mapping
+	Address  uint64
+	Line     []Line
+	IsFolded bool
+
+	mappingIDX uint64
+}
+
+// Line corresponds to Profile.Line
+type Line struct {
+	Function *Function
+	Line     int64
+
+	functionIDX uint64
+}
+
+// Function corresponds to Profile.Function
+type Function struct {
+	ID         uint64
+	Name       string
+	SystemName string
+	Filename   string
+	StartLine  int64
+
+	nameX       int64
+	systemNameX int64
+	filenameX   int64
+}
+
+// Parse parses a profile and checks for its validity. The input
+// may be a gzip-compressed encoded protobuf or one of many legacy
+// profile formats which may be unsupported in the future.
+func Parse(r io.Reader) (*Profile, error) {
+	orig, err := io.ReadAll(r)
+	if err != nil {
+		return nil, err
+	}
+
+	var p *Profile
+	if len(orig) >= 2 && orig[0] == 0x1f && orig[1] == 0x8b {
+		gz, err := gzip.NewReader(bytes.NewBuffer(orig))
+		if err != nil {
+			return nil, fmt.Errorf("decompressing profile: %v", err)
+		}
+		data, err := io.ReadAll(gz)
+		if err != nil {
+			return nil, fmt.Errorf("decompressing profile: %v", err)
+		}
+		orig = data
+	}
+	if p, err = parseUncompressed(orig); err != nil {
+		if p, err = parseLegacy(orig); err != nil {
+			return nil, fmt.Errorf("parsing profile: %v", err)
+		}
+	}
+
+	if err := p.CheckValid(); err != nil {
+		return nil, fmt.Errorf("malformed profile: %v", err)
+	}
+	return p, nil
+}
+
+var errUnrecognized = fmt.Errorf("unrecognized profile format")
+var errMalformed = fmt.Errorf("malformed profile format")
+
+func parseLegacy(data []byte) (*Profile, error) {
+	parsers := []func([]byte) (*Profile, error){
+		parseCPU,
+		parseHeap,
+		parseGoCount, // goroutine, threadcreate
+		parseThread,
+		parseContention,
+	}
+
+	for _, parser := range parsers {
+		p, err := parser(data)
+		if err == nil {
+			p.setMain()
+			p.addLegacyFrameInfo()
+			return p, nil
+		}
+		if err != errUnrecognized {
+			return nil, err
+		}
+	}
+	return nil, errUnrecognized
+}
+
+func parseUncompressed(data []byte) (*Profile, error) {
+	p := &Profile{}
+	if err := unmarshal(data, p); err != nil {
+		return nil, err
+	}
+
+	if err := p.postDecode(); err != nil {
+		return nil, err
+	}
+
+	return p, nil
+}
+
+var libRx = regexp.MustCompile(`([.]so$|[.]so[._][0-9]+)`)
+
+// setMain scans Mapping entries and guesses which entry is main
+// because legacy profiles don't obey the convention of putting main
+// first.
+func (p *Profile) setMain() {
+	for i := 0; i < len(p.Mapping); i++ {
+		file := strings.TrimSpace(strings.ReplaceAll(p.Mapping[i].File, "(deleted)", ""))
+		if len(file) == 0 {
+			continue
+		}
+		if len(libRx.FindStringSubmatch(file)) > 0 {
+			continue
+		}
+		if strings.HasPrefix(file, "[") {
+			continue
+		}
+		// Swap what we guess is main to position 0.
+		p.Mapping[i], p.Mapping[0] = p.Mapping[0], p.Mapping[i]
+		break
+	}
+}
+
+// Write writes the profile as a gzip-compressed marshaled protobuf.
+func (p *Profile) Write(w io.Writer) error {
+	p.preEncode()
+	b := marshal(p)
+	zw := gzip.NewWriter(w)
+	defer zw.Close()
+	_, err := zw.Write(b)
+	return err
+}
+
+// CheckValid tests whether the profile is valid. Checks include, but are
+// not limited to:
+//   - len(Profile.Sample[n].value) == len(Profile.value_unit)
+//   - Sample.id has a corresponding Profile.Location
+func (p *Profile) CheckValid() error {
+	// Check that sample values are consistent
+	sampleLen := len(p.SampleType)
+	if sampleLen == 0 && len(p.Sample) != 0 {
+		return fmt.Errorf("missing sample type information")
+	}
+	for _, s := range p.Sample {
+		if len(s.Value) != sampleLen {
+			return fmt.Errorf("mismatch: sample has: %d values vs. %d types", len(s.Value), len(p.SampleType))
+		}
+	}
+
+	// Check that all mappings/locations/functions are in the tables
+	// Check that there are no duplicate ids
+	mappings := make(map[uint64]*Mapping, len(p.Mapping))
+	for _, m := range p.Mapping {
+		if m.ID == 0 {
+			return fmt.Errorf("found mapping with reserved ID=0")
+		}
+		if mappings[m.ID] != nil {
+			return fmt.Errorf("multiple mappings with same id: %d", m.ID)
+		}
+		mappings[m.ID] = m
+	}
+	functions := make(map[uint64]*Function, len(p.Function))
+	for _, f := range p.Function {
+		if f.ID == 0 {
+			return fmt.Errorf("found function with reserved ID=0")
+		}
+		if functions[f.ID] != nil {
+			return fmt.Errorf("multiple functions with same id: %d", f.ID)
+		}
+		functions[f.ID] = f
+	}
+	locations := make(map[uint64]*Location, len(p.Location))
+	for _, l := range p.Location {
+		if l.ID == 0 {
+			return fmt.Errorf("found location with reserved id=0")
+		}
+		if locations[l.ID] != nil {
+			return fmt.Errorf("multiple locations with same id: %d", l.ID)
+		}
+		locations[l.ID] = l
+		if m := l.Mapping; m != nil {
+			if m.ID == 0 || mappings[m.ID] != m {
+				return fmt.Errorf("inconsistent mapping %p: %d", m, m.ID)
+			}
+		}
+		for _, ln := range l.Line {
+			if f := ln.Function; f != nil {
+				if f.ID == 0 || functions[f.ID] != f {
+					return fmt.Errorf("inconsistent function %p: %d", f, f.ID)
+				}
+			}
+		}
+	}
+	return nil
+}
+
+// Aggregate merges the locations in the profile into equivalence
+// classes preserving the request attributes. It also updates the
+// samples to point to the merged locations.
+func (p *Profile) Aggregate(inlineFrame, function, filename, linenumber, address bool) error {
+	for _, m := range p.Mapping {
+		m.HasInlineFrames = m.HasInlineFrames && inlineFrame
+		m.HasFunctions = m.HasFunctions && function
+		m.HasFilenames = m.HasFilenames && filename
+		m.HasLineNumbers = m.HasLineNumbers && linenumber
+	}
+
+	// Aggregate functions
+	if !function || !filename {
+		for _, f := range p.Function {
+			if !function {
+				f.Name = ""
+				f.SystemName = ""
+			}
+			if !filename {
+				f.Filename = ""
+			}
+		}
+	}
+
+	// Aggregate locations
+	if !inlineFrame || !address || !linenumber {
+		for _, l := range p.Location {
+			if !inlineFrame && len(l.Line) > 1 {
+				l.Line = l.Line[len(l.Line)-1:]
+			}
+			if !linenumber {
+				for i := range l.Line {
+					l.Line[i].Line = 0
+				}
+			}
+			if !address {
+				l.Address = 0
+			}
+		}
+	}
+
+	return p.CheckValid()
+}
+
+// Print dumps a text representation of a profile. Intended mainly
+// for debugging purposes.
+func (p *Profile) String() string {
+
+	ss := make([]string, 0, len(p.Sample)+len(p.Mapping)+len(p.Location))
+	if pt := p.PeriodType; pt != nil {
+		ss = append(ss, fmt.Sprintf("PeriodType: %s %s", pt.Type, pt.Unit))
+	}
+	ss = append(ss, fmt.Sprintf("Period: %d", p.Period))
+	if p.TimeNanos != 0 {
+		ss = append(ss, fmt.Sprintf("Time: %v", time.Unix(0, p.TimeNanos)))
+	}
+	if p.DurationNanos != 0 {
+		ss = append(ss, fmt.Sprintf("Duration: %v", time.Duration(p.DurationNanos)))
+	}
+
+	ss = append(ss, "Samples:")
+	var sh1 string
+	for _, s := range p.SampleType {
+		sh1 = sh1 + fmt.Sprintf("%s/%s ", s.Type, s.Unit)
+	}
+	ss = append(ss, strings.TrimSpace(sh1))
+	for _, s := range p.Sample {
+		var sv string
+		for _, v := range s.Value {
+			sv = fmt.Sprintf("%s %10d", sv, v)
+		}
+		sv = sv + ": "
+		for _, l := range s.Location {
+			sv = sv + fmt.Sprintf("%d ", l.ID)
+		}
+		ss = append(ss, sv)
+		const labelHeader = "                "
+		if len(s.Label) > 0 {
+			ls := labelHeader
+			for k, v := range s.Label {
+				ls = ls + fmt.Sprintf("%s:%v ", k, v)
+			}
+			ss = append(ss, ls)
+		}
+		if len(s.NumLabel) > 0 {
+			ls := labelHeader
+			for k, v := range s.NumLabel {
+				ls = ls + fmt.Sprintf("%s:%v ", k, v)
+			}
+			ss = append(ss, ls)
+		}
+	}
+
+	ss = append(ss, "Locations")
+	for _, l := range p.Location {
+		locStr := fmt.Sprintf("%6d: %#x ", l.ID, l.Address)
+		if m := l.Mapping; m != nil {
+			locStr = locStr + fmt.Sprintf("M=%d ", m.ID)
+		}
+		if len(l.Line) == 0 {
+			ss = append(ss, locStr)
+		}
+		for li := range l.Line {
+			lnStr := "??"
+			if fn := l.Line[li].Function; fn != nil {
+				lnStr = fmt.Sprintf("%s %s:%d s=%d",
+					fn.Name,
+					fn.Filename,
+					l.Line[li].Line,
+					fn.StartLine)
+				if fn.Name != fn.SystemName {
+					lnStr = lnStr + "(" + fn.SystemName + ")"
+				}
+			}
+			ss = append(ss, locStr+lnStr)
+			// Do not print location details past the first line
+			locStr = "             "
+		}
+	}
+
+	ss = append(ss, "Mappings")
+	for _, m := range p.Mapping {
+		bits := ""
+		if m.HasFunctions {
+			bits += "[FN]"
+		}
+		if m.HasFilenames {
+			bits += "[FL]"
+		}
+		if m.HasLineNumbers {
+			bits += "[LN]"
+		}
+		if m.HasInlineFrames {
+			bits += "[IN]"
+		}
+		ss = append(ss, fmt.Sprintf("%d: %#x/%#x/%#x %s %s %s",
+			m.ID,
+			m.Start, m.Limit, m.Offset,
+			m.File,
+			m.BuildID,
+			bits))
+	}
+
+	return strings.Join(ss, "\n") + "\n"
+}
+
+// Merge adds profile p adjusted by ratio r into profile p. Profiles
+// must be compatible (same Type and SampleType).
+// TODO(rsilvera): consider normalizing the profiles based on the
+// total samples collected.
+func (p *Profile) Merge(pb *Profile, r float64) error {
+	if err := p.Compatible(pb); err != nil {
+		return err
+	}
+
+	pb = pb.Copy()
+
+	// Keep the largest of the two periods.
+	if pb.Period > p.Period {
+		p.Period = pb.Period
+	}
+
+	p.DurationNanos += pb.DurationNanos
+
+	p.Mapping = append(p.Mapping, pb.Mapping...)
+	for i, m := range p.Mapping {
+		m.ID = uint64(i + 1)
+	}
+	p.Location = append(p.Location, pb.Location...)
+	for i, l := range p.Location {
+		l.ID = uint64(i + 1)
+	}
+	p.Function = append(p.Function, pb.Function...)
+	for i, f := range p.Function {
+		f.ID = uint64(i + 1)
+	}
+
+	if r != 1.0 {
+		for _, s := range pb.Sample {
+			for i, v := range s.Value {
+				s.Value[i] = int64((float64(v) * r))
+			}
+		}
+	}
+	p.Sample = append(p.Sample, pb.Sample...)
+	return p.CheckValid()
+}
+
+// Compatible determines if two profiles can be compared/merged.
+// returns nil if the profiles are compatible; otherwise an error with
+// details on the incompatibility.
+func (p *Profile) Compatible(pb *Profile) error {
+	if !compatibleValueTypes(p.PeriodType, pb.PeriodType) {
+		return fmt.Errorf("incompatible period types %v and %v", p.PeriodType, pb.PeriodType)
+	}
+
+	if len(p.SampleType) != len(pb.SampleType) {
+		return fmt.Errorf("incompatible sample types %v and %v", p.SampleType, pb.SampleType)
+	}
+
+	for i := range p.SampleType {
+		if !compatibleValueTypes(p.SampleType[i], pb.SampleType[i]) {
+			return fmt.Errorf("incompatible sample types %v and %v", p.SampleType, pb.SampleType)
+		}
+	}
+
+	return nil
+}
+
+// HasFunctions determines if all locations in this profile have
+// symbolized function information.
+func (p *Profile) HasFunctions() bool {
+	for _, l := range p.Location {
+		if l.Mapping == nil || !l.Mapping.HasFunctions {
+			return false
+		}
+	}
+	return true
+}
+
+// HasFileLines determines if all locations in this profile have
+// symbolized file and line number information.
+func (p *Profile) HasFileLines() bool {
+	for _, l := range p.Location {
+		if l.Mapping == nil || (!l.Mapping.HasFilenames || !l.Mapping.HasLineNumbers) {
+			return false
+		}
+	}
+	return true
+}
+
+func compatibleValueTypes(v1, v2 *ValueType) bool {
+	if v1 == nil || v2 == nil {
+		return true // No grounds to disqualify.
+	}
+	return v1.Type == v2.Type && v1.Unit == v2.Unit
+}
+
+// Copy makes a fully independent copy of a profile.
+func (p *Profile) Copy() *Profile {
+	p.preEncode()
+	b := marshal(p)
+
+	pp := &Profile{}
+	if err := unmarshal(b, pp); err != nil {
+		panic(err)
+	}
+	if err := pp.postDecode(); err != nil {
+		panic(err)
+	}
+
+	return pp
+}
+
+// Demangler maps symbol names to a human-readable form. This may
+// include C++ demangling and additional simplification. Names that
+// are not demangled may be missing from the resulting map.
+type Demangler func(name []string) (map[string]string, error)
+
+// Demangle attempts to demangle and optionally simplify any function
+// names referenced in the profile. It works on a best-effort basis:
+// it will silently preserve the original names in case of any errors.
+func (p *Profile) Demangle(d Demangler) error {
+	// Collect names to demangle.
+	var names []string
+	for _, fn := range p.Function {
+		names = append(names, fn.SystemName)
+	}
+
+	// Update profile with demangled names.
+	demangled, err := d(names)
+	if err != nil {
+		return err
+	}
+	for _, fn := range p.Function {
+		if dd, ok := demangled[fn.SystemName]; ok {
+			fn.Name = dd
+		}
+	}
+	return nil
+}
+
+// Empty reports whether the profile contains no samples.
+func (p *Profile) Empty() bool {
+	return len(p.Sample) == 0
+}
+
+// Scale multiplies all sample values in a profile by a constant.
+func (p *Profile) Scale(ratio float64) {
+	if ratio == 1 {
+		return
+	}
+	ratios := make([]float64, len(p.SampleType))
+	for i := range p.SampleType {
+		ratios[i] = ratio
+	}
+	p.ScaleN(ratios)
+}
+
+// ScaleN multiplies each sample values in a sample by a different amount.
+func (p *Profile) ScaleN(ratios []float64) error {
+	if len(p.SampleType) != len(ratios) {
+		return fmt.Errorf("mismatched scale ratios, got %d, want %d", len(ratios), len(p.SampleType))
+	}
+	allOnes := true
+	for _, r := range ratios {
+		if r != 1 {
+			allOnes = false
+			break
+		}
+	}
+	if allOnes {
+		return nil
+	}
+	for _, s := range p.Sample {
+		for i, v := range s.Value {
+			if ratios[i] != 1 {
+				s.Value[i] = int64(float64(v) * ratios[i])
+			}
+		}
+	}
+	return nil
+}
diff --git a/contrib/go/_std_1.20/src/internal/profile/proto.go b/contrib/go/_std_1.20/src/internal/profile/proto.go
new file mode 100644
index 0000000000..58ff0ad2e0
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/profile/proto.go
@@ -0,0 +1,356 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file is a simple protocol buffer encoder and decoder.
+//
+// A protocol message must implement the message interface:
+//   decoder() []decoder
+//   encode(*buffer)
+//
+// The decode method returns a slice indexed by field number that gives the
+// function to decode that field.
+// The encode method encodes its receiver into the given buffer.
+//
+// The two methods are simple enough to be implemented by hand rather than
+// by using a protocol compiler.
+//
+// See profile.go for examples of messages implementing this interface.
+//
+// There is no support for groups, message sets, or "has" bits.
+
+package profile
+
+import (
+	"errors"
+	"fmt"
+)
+
+type buffer struct {
+	field int
+	typ   int
+	u64   uint64
+	data  []byte
+	tmp   [16]byte
+}
+
+type decoder func(*buffer, message) error
+
+type message interface {
+	decoder() []decoder
+	encode(*buffer)
+}
+
+func marshal(m message) []byte {
+	var b buffer
+	m.encode(&b)
+	return b.data
+}
+
+func encodeVarint(b *buffer, x uint64) {
+	for x >= 128 {
+		b.data = append(b.data, byte(x)|0x80)
+		x >>= 7
+	}
+	b.data = append(b.data, byte(x))
+}
+
+func encodeLength(b *buffer, tag int, len int) {
+	encodeVarint(b, uint64(tag)<<3|2)
+	encodeVarint(b, uint64(len))
+}
+
+func encodeUint64(b *buffer, tag int, x uint64) {
+	// append varint to b.data
+	encodeVarint(b, uint64(tag)<<3|0)
+	encodeVarint(b, x)
+}
+
+func encodeUint64s(b *buffer, tag int, x []uint64) {
+	if len(x) > 2 {
+		// Use packed encoding
+		n1 := len(b.data)
+		for _, u := range x {
+			encodeVarint(b, u)
+		}
+		n2 := len(b.data)
+		encodeLength(b, tag, n2-n1)
+		n3 := len(b.data)
+		copy(b.tmp[:], b.data[n2:n3])
+		copy(b.data[n1+(n3-n2):], b.data[n1:n2])
+		copy(b.data[n1:], b.tmp[:n3-n2])
+		return
+	}
+	for _, u := range x {
+		encodeUint64(b, tag, u)
+	}
+}
+
+func encodeUint64Opt(b *buffer, tag int, x uint64) {
+	if x == 0 {
+		return
+	}
+	encodeUint64(b, tag, x)
+}
+
+func encodeInt64(b *buffer, tag int, x int64) {
+	u := uint64(x)
+	encodeUint64(b, tag, u)
+}
+
+func encodeInt64Opt(b *buffer, tag int, x int64) {
+	if x == 0 {
+		return
+	}
+	encodeInt64(b, tag, x)
+}
+
+func encodeInt64s(b *buffer, tag int, x []int64) {
+	if len(x) > 2 {
+		// Use packed encoding
+		n1 := len(b.data)
+		for _, u := range x {
+			encodeVarint(b, uint64(u))
+		}
+		n2 := len(b.data)
+		encodeLength(b, tag, n2-n1)
+		n3 := len(b.data)
+		copy(b.tmp[:], b.data[n2:n3])
+		copy(b.data[n1+(n3-n2):], b.data[n1:n2])
+		copy(b.data[n1:], b.tmp[:n3-n2])
+		return
+	}
+	for _, u := range x {
+		encodeInt64(b, tag, u)
+	}
+}
+
+func encodeString(b *buffer, tag int, x string) {
+	encodeLength(b, tag, len(x))
+	b.data = append(b.data, x...)
+}
+
+func encodeStrings(b *buffer, tag int, x []string) {
+	for _, s := range x {
+		encodeString(b, tag, s)
+	}
+}
+
+func encodeBool(b *buffer, tag int, x bool) {
+	if x {
+		encodeUint64(b, tag, 1)
+	} else {
+		encodeUint64(b, tag, 0)
+	}
+}
+
+func encodeBoolOpt(b *buffer, tag int, x bool) {
+	if !x {
+		return
+	}
+	encodeBool(b, tag, x)
+}
+
+func encodeMessage(b *buffer, tag int, m message) {
+	n1 := len(b.data)
+	m.encode(b)
+	n2 := len(b.data)
+	encodeLength(b, tag, n2-n1)
+	n3 := len(b.data)
+	copy(b.tmp[:], b.data[n2:n3])
+	copy(b.data[n1+(n3-n2):], b.data[n1:n2])
+	copy(b.data[n1:], b.tmp[:n3-n2])
+}
+
+func unmarshal(data []byte, m message) (err error) {
+	b := buffer{data: data, typ: 2}
+	return decodeMessage(&b, m)
+}
+
+func le64(p []byte) uint64 {
+	return uint64(p[0]) | uint64(p[1])<<8 | uint64(p[2])<<16 | uint64(p[3])<<24 | uint64(p[4])<<32 | uint64(p[5])<<40 | uint64(p[6])<<48 | uint64(p[7])<<56
+}
+
+func le32(p []byte) uint32 {
+	return uint32(p[0]) | uint32(p[1])<<8 | uint32(p[2])<<16 | uint32(p[3])<<24
+}
+
+func decodeVarint(data []byte) (uint64, []byte, error) {
+	var i int
+	var u uint64
+	for i = 0; ; i++ {
+		if i >= 10 || i >= len(data) {
+			return 0, nil, errors.New("bad varint")
+		}
+		u |= uint64(data[i]&0x7F) << uint(7*i)
+		if data[i]&0x80 == 0 {
+			return u, data[i+1:], nil
+		}
+	}
+}
+
+func decodeField(b *buffer, data []byte) ([]byte, error) {
+	x, data, err := decodeVarint(data)
+	if err != nil {
+		return nil, err
+	}
+	b.field = int(x >> 3)
+	b.typ = int(x & 7)
+	b.data = nil
+	b.u64 = 0
+	switch b.typ {
+	case 0:
+		b.u64, data, err = decodeVarint(data)
+		if err != nil {
+			return nil, err
+		}
+	case 1:
+		if len(data) < 8 {
+			return nil, errors.New("not enough data")
+		}
+		b.u64 = le64(data[:8])
+		data = data[8:]
+	case 2:
+		var n uint64
+		n, data, err = decodeVarint(data)
+		if err != nil {
+			return nil, err
+		}
+		if n > uint64(len(data)) {
+			return nil, errors.New("too much data")
+		}
+		b.data = data[:n]
+		data = data[n:]
+	case 5:
+		if len(data) < 4 {
+			return nil, errors.New("not enough data")
+		}
+		b.u64 = uint64(le32(data[:4]))
+		data = data[4:]
+	default:
+		return nil, fmt.Errorf("unknown wire type: %d", b.typ)
+	}
+
+	return data, nil
+}
+
+func checkType(b *buffer, typ int) error {
+	if b.typ != typ {
+		return errors.New("type mismatch")
+	}
+	return nil
+}
+
+func decodeMessage(b *buffer, m message) error {
+	if err := checkType(b, 2); err != nil {
+		return err
+	}
+	dec := m.decoder()
+	data := b.data
+	for len(data) > 0 {
+		// pull varint field# + type
+		var err error
+		data, err = decodeField(b, data)
+		if err != nil {
+			return err
+		}
+		if b.field >= len(dec) || dec[b.field] == nil {
+			continue
+		}
+		if err := dec[b.field](b, m); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func decodeInt64(b *buffer, x *int64) error {
+	if err := checkType(b, 0); err != nil {
+		return err
+	}
+	*x = int64(b.u64)
+	return nil
+}
+
+func decodeInt64s(b *buffer, x *[]int64) error {
+	if b.typ == 2 {
+		// Packed encoding
+		data := b.data
+		for len(data) > 0 {
+			var u uint64
+			var err error
+
+			if u, data, err = decodeVarint(data); err != nil {
+				return err
+			}
+			*x = append(*x, int64(u))
+		}
+		return nil
+	}
+	var i int64
+	if err := decodeInt64(b, &i); err != nil {
+		return err
+	}
+	*x = append(*x, i)
+	return nil
+}
+
+func decodeUint64(b *buffer, x *uint64) error {
+	if err := checkType(b, 0); err != nil {
+		return err
+	}
+	*x = b.u64
+	return nil
+}
+
+func decodeUint64s(b *buffer, x *[]uint64) error {
+	if b.typ == 2 {
+		data := b.data
+		// Packed encoding
+		for len(data) > 0 {
+			var u uint64
+			var err error
+
+			if u, data, err = decodeVarint(data); err != nil {
+				return err
+			}
+			*x = append(*x, u)
+		}
+		return nil
+	}
+	var u uint64
+	if err := decodeUint64(b, &u); err != nil {
+		return err
+	}
+	*x = append(*x, u)
+	return nil
+}
+
+func decodeString(b *buffer, x *string) error {
+	if err := checkType(b, 2); err != nil {
+		return err
+	}
+	*x = string(b.data)
+	return nil
+}
+
+func decodeStrings(b *buffer, x *[]string) error {
+	var s string
+	if err := decodeString(b, &s); err != nil {
+		return err
+	}
+	*x = append(*x, s)
+	return nil
+}
+
+func decodeBool(b *buffer, x *bool) error {
+	if err := checkType(b, 0); err != nil {
+		return err
+	}
+	if int64(b.u64) == 0 {
+		*x = false
+	} else {
+		*x = true
+	}
+	return nil
+}
diff --git a/contrib/go/_std_1.20/src/internal/profile/prune.go b/contrib/go/_std_1.20/src/internal/profile/prune.go
new file mode 100644
index 0000000000..1924fada7a
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/profile/prune.go
@@ -0,0 +1,97 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Implements methods to remove frames from profiles.
+
+package profile
+
+import (
+	"fmt"
+	"regexp"
+)
+
+// Prune removes all nodes beneath a node matching dropRx, and not
+// matching keepRx. If the root node of a Sample matches, the sample
+// will have an empty stack.
+func (p *Profile) Prune(dropRx, keepRx *regexp.Regexp) {
+	prune := make(map[uint64]bool)
+	pruneBeneath := make(map[uint64]bool)
+
+	for _, loc := range p.Location {
+		var i int
+		for i = len(loc.Line) - 1; i >= 0; i-- {
+			if fn := loc.Line[i].Function; fn != nil && fn.Name != "" {
+				funcName := fn.Name
+				// Account for leading '.' on the PPC ELF v1 ABI.
+				if funcName[0] == '.' {
+					funcName = funcName[1:]
+				}
+				if dropRx.MatchString(funcName) {
+					if keepRx == nil || !keepRx.MatchString(funcName) {
+						break
+					}
+				}
+			}
+		}
+
+		if i >= 0 {
+			// Found matching entry to prune.
+			pruneBeneath[loc.ID] = true
+
+			// Remove the matching location.
+			if i == len(loc.Line)-1 {
+				// Matched the top entry: prune the whole location.
+				prune[loc.ID] = true
+			} else {
+				loc.Line = loc.Line[i+1:]
+			}
+		}
+	}
+
+	// Prune locs from each Sample
+	for _, sample := range p.Sample {
+		// Scan from the root to the leaves to find the prune location.
+		// Do not prune frames before the first user frame, to avoid
+		// pruning everything.
+		foundUser := false
+		for i := len(sample.Location) - 1; i >= 0; i-- {
+			id := sample.Location[i].ID
+			if !prune[id] && !pruneBeneath[id] {
+				foundUser = true
+				continue
+			}
+			if !foundUser {
+				continue
+			}
+			if prune[id] {
+				sample.Location = sample.Location[i+1:]
+				break
+			}
+			if pruneBeneath[id] {
+				sample.Location = sample.Location[i:]
+				break
+			}
+		}
+	}
+}
+
+// RemoveUninteresting prunes and elides profiles using built-in
+// tables of uninteresting function names.
+func (p *Profile) RemoveUninteresting() error {
+	var keep, drop *regexp.Regexp
+	var err error
+
+	if p.DropFrames != "" {
+		if drop, err = regexp.Compile("^(" + p.DropFrames + ")$"); err != nil {
+			return fmt.Errorf("failed to compile regexp %s: %v", p.DropFrames, err)
+		}
+		if p.KeepFrames != "" {
+			if keep, err = regexp.Compile("^(" + p.KeepFrames + ")$"); err != nil {
+				return fmt.Errorf("failed to compile regexp %s: %v", p.KeepFrames, err)
+			}
+		}
+		p.Prune(drop, keep)
+	}
+	return nil
+}
diff --git a/contrib/go/_std_1.20/src/internal/profile/ya.make b/contrib/go/_std_1.20/src/internal/profile/ya.make
new file mode 100644
index 0000000000..3074ea06c3
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/profile/ya.make
@@ -0,0 +1,13 @@
+GO_LIBRARY()
+
+SRCS(
+    encode.go
+    filter.go
+    legacy_profile.go
+    merge.go
+    profile.go
+    proto.go
+    prune.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/race/doc.go b/contrib/go/_std_1.20/src/internal/race/doc.go
new file mode 100644
index 0000000000..8fa44ce6f1
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/race/doc.go
@@ -0,0 +1,11 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+/*
+Package race contains helper functions for manually instrumenting code for the race detector.
+
+The runtime package intentionally exports these functions only in the race build;
+this package exports them unconditionally but without the "race" build tag they are no-ops.
+*/
+package race
diff --git a/contrib/go/_std_1.20/src/internal/race/norace.go b/contrib/go/_std_1.20/src/internal/race/norace.go
new file mode 100644
index 0000000000..67b1305713
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/race/norace.go
@@ -0,0 +1,43 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !race
+// +build !race
+
+package race
+
+import (
+	"unsafe"
+)
+
+const Enabled = false
+
+func Acquire(addr unsafe.Pointer) {
+}
+
+func Release(addr unsafe.Pointer) {
+}
+
+func ReleaseMerge(addr unsafe.Pointer) {
+}
+
+func Disable() {
+}
+
+func Enable() {
+}
+
+func Read(addr unsafe.Pointer) {
+}
+
+func Write(addr unsafe.Pointer) {
+}
+
+func ReadRange(addr unsafe.Pointer, len int) {
+}
+
+func WriteRange(addr unsafe.Pointer, len int) {
+}
+
+func Errors() int { return 0 }
diff --git a/contrib/go/_std_1.20/src/internal/race/ya.make b/contrib/go/_std_1.20/src/internal/race/ya.make
new file mode 100644
index 0000000000..e7b39e2415
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/race/ya.make
@@ -0,0 +1,23 @@
+GO_LIBRARY()
+
+SRCS(
+    doc.go
+)
+
+IF (RACE)
+    IF (CGO_ENABLED OR OS_DARWIN)
+        SRCS(
+            race.go
+        )
+    ELSE()
+        SRCS(
+            norace.go
+        )
+    ENDIF()
+ELSE()
+    SRCS(
+        norace.go
+    )
+ENDIF()
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/reflectlite/asm.s b/contrib/go/_std_1.20/src/internal/reflectlite/asm.s
new file mode 100644
index 0000000000..a7b69b65ba
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/reflectlite/asm.s
@@ -0,0 +1,5 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Trigger build without complete flag.
\ No newline at end of file
diff --git a/contrib/go/_std_1.20/src/internal/reflectlite/swapper.go b/contrib/go/_std_1.20/src/internal/reflectlite/swapper.go
new file mode 100644
index 0000000000..fc402bb38a
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/reflectlite/swapper.go
@@ -0,0 +1,78 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package reflectlite
+
+import (
+	"internal/goarch"
+	"internal/unsafeheader"
+	"unsafe"
+)
+
+// Swapper returns a function that swaps the elements in the provided
+// slice.
+//
+// Swapper panics if the provided interface is not a slice.
+func Swapper(slice any) func(i, j int) {
+	v := ValueOf(slice)
+	if v.Kind() != Slice {
+		panic(&ValueError{Method: "Swapper", Kind: v.Kind()})
+	}
+	// Fast path for slices of size 0 and 1. Nothing to swap.
+	switch v.Len() {
+	case 0:
+		return func(i, j int) { panic("reflect: slice index out of range") }
+	case 1:
+		return func(i, j int) {
+			if i != 0 || j != 0 {
+				panic("reflect: slice index out of range")
+			}
+		}
+	}
+
+	typ := v.Type().Elem().(*rtype)
+	size := typ.Size()
+	hasPtr := typ.ptrdata != 0
+
+	// Some common & small cases, without using memmove:
+	if hasPtr {
+		if size == goarch.PtrSize {
+			ps := *(*[]unsafe.Pointer)(v.ptr)
+			return func(i, j int) { ps[i], ps[j] = ps[j], ps[i] }
+		}
+		if typ.Kind() == String {
+			ss := *(*[]string)(v.ptr)
+			return func(i, j int) { ss[i], ss[j] = ss[j], ss[i] }
+		}
+	} else {
+		switch size {
+		case 8:
+			is := *(*[]int64)(v.ptr)
+			return func(i, j int) { is[i], is[j] = is[j], is[i] }
+		case 4:
+			is := *(*[]int32)(v.ptr)
+			return func(i, j int) { is[i], is[j] = is[j], is[i] }
+		case 2:
+			is := *(*[]int16)(v.ptr)
+			return func(i, j int) { is[i], is[j] = is[j], is[i] }
+		case 1:
+			is := *(*[]int8)(v.ptr)
+			return func(i, j int) { is[i], is[j] = is[j], is[i] }
+		}
+	}
+
+	s := (*unsafeheader.Slice)(v.ptr)
+	tmp := unsafe_New(typ) // swap scratch space
+
+	return func(i, j int) {
+		if uint(i) >= uint(s.Len) || uint(j) >= uint(s.Len) {
+			panic("reflect: slice index out of range")
+		}
+		val1 := arrayAt(s.Data, i, size, "i < s.Len")
+		val2 := arrayAt(s.Data, j, size, "j < s.Len")
+		typedmemmove(typ, tmp, val1)
+		typedmemmove(typ, val1, val2)
+		typedmemmove(typ, val2, tmp)
+	}
+}
diff --git a/contrib/go/_std_1.20/src/internal/reflectlite/type.go b/contrib/go/_std_1.20/src/internal/reflectlite/type.go
new file mode 100644
index 0000000000..43440b1126
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/reflectlite/type.go
@@ -0,0 +1,974 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package reflectlite implements lightweight version of reflect, not using
+// any package except for "runtime" and "unsafe".
+package reflectlite
+
+import "unsafe"
+
+// Type is the representation of a Go type.
+//
+// Not all methods apply to all kinds of types. Restrictions,
+// if any, are noted in the documentation for each method.
+// Use the Kind method to find out the kind of type before
+// calling kind-specific methods. Calling a method
+// inappropriate to the kind of type causes a run-time panic.
+//
+// Type values are comparable, such as with the == operator,
+// so they can be used as map keys.
+// Two Type values are equal if they represent identical types.
+type Type interface {
+	// Methods applicable to all types.
+
+	// Name returns the type's name within its package for a defined type.
+	// For other (non-defined) types it returns the empty string.
+	Name() string
+
+	// PkgPath returns a defined type's package path, that is, the import path
+	// that uniquely identifies the package, such as "encoding/base64".
+	// If the type was predeclared (string, error) or not defined (*T, struct{},
+	// []int, or A where A is an alias for a non-defined type), the package path
+	// will be the empty string.
+	PkgPath() string
+
+	// Size returns the number of bytes needed to store
+	// a value of the given type; it is analogous to unsafe.Sizeof.
+	Size() uintptr
+
+	// Kind returns the specific kind of this type.
+	Kind() Kind
+
+	// Implements reports whether the type implements the interface type u.
+	Implements(u Type) bool
+
+	// AssignableTo reports whether a value of the type is assignable to type u.
+	AssignableTo(u Type) bool
+
+	// Comparable reports whether values of this type are comparable.
+	Comparable() bool
+
+	// String returns a string representation of the type.
+	// The string representation may use shortened package names
+	// (e.g., base64 instead of "encoding/base64") and is not
+	// guaranteed to be unique among types. To test for type identity,
+	// compare the Types directly.
+	String() string
+
+	// Elem returns a type's element type.
+	// It panics if the type's Kind is not Ptr.
+	Elem() Type
+
+	common() *rtype
+	uncommon() *uncommonType
+}
+
+/*
+ * These data structures are known to the compiler (../../cmd/internal/reflectdata/reflect.go).
+ * A few are known to ../runtime/type.go to convey to debuggers.
+ * They are also known to ../runtime/type.go.
+ */
+
+// A Kind represents the specific kind of type that a Type represents.
+// The zero Kind is not a valid kind.
+type Kind uint
+
+const (
+	Invalid Kind = iota
+	Bool
+	Int
+	Int8
+	Int16
+	Int32
+	Int64
+	Uint
+	Uint8
+	Uint16
+	Uint32
+	Uint64
+	Uintptr
+	Float32
+	Float64
+	Complex64
+	Complex128
+	Array
+	Chan
+	Func
+	Interface
+	Map
+	Pointer
+	Slice
+	String
+	Struct
+	UnsafePointer
+)
+
+const Ptr = Pointer
+
+// tflag is used by an rtype to signal what extra type information is
+// available in the memory directly following the rtype value.
+//
+// tflag values must be kept in sync with copies in:
+//
+//	cmd/compile/internal/reflectdata/reflect.go
+//	cmd/link/internal/ld/decodesym.go
+//	runtime/type.go
+type tflag uint8
+
+const (
+	// tflagUncommon means that there is a pointer, *uncommonType,
+	// just beyond the outer type structure.
+	//
+	// For example, if t.Kind() == Struct and t.tflag&tflagUncommon != 0,
+	// then t has uncommonType data and it can be accessed as:
+	//
+	//	type tUncommon struct {
+	//		structType
+	//		u uncommonType
+	//	}
+	//	u := &(*tUncommon)(unsafe.Pointer(t)).u
+	tflagUncommon tflag = 1 << 0
+
+	// tflagExtraStar means the name in the str field has an
+	// extraneous '*' prefix. This is because for most types T in
+	// a program, the type *T also exists and reusing the str data
+	// saves binary size.
+	tflagExtraStar tflag = 1 << 1
+
+	// tflagNamed means the type has a name.
+	tflagNamed tflag = 1 << 2
+
+	// tflagRegularMemory means that equal and hash functions can treat
+	// this type as a single region of t.size bytes.
+	tflagRegularMemory tflag = 1 << 3
+)
+
+// rtype is the common implementation of most values.
+// It is embedded in other struct types.
+//
+// rtype must be kept in sync with ../runtime/type.go:/^type._type.
+type rtype struct {
+	size       uintptr
+	ptrdata    uintptr // number of bytes in the type that can contain pointers
+	hash       uint32  // hash of type; avoids computation in hash tables
+	tflag      tflag   // extra type information flags
+	align      uint8   // alignment of variable with this type
+	fieldAlign uint8   // alignment of struct field with this type
+	kind       uint8   // enumeration for C
+	// function for comparing objects of this type
+	// (ptr to object A, ptr to object B) -> ==?
+	equal     func(unsafe.Pointer, unsafe.Pointer) bool
+	gcdata    *byte   // garbage collection data
+	str       nameOff // string form
+	ptrToThis typeOff // type for pointer to this type, may be zero
+}
+
+// Method on non-interface type
+type method struct {
+	name nameOff // name of method
+	mtyp typeOff // method type (without receiver)
+	ifn  textOff // fn used in interface call (one-word receiver)
+	tfn  textOff // fn used for normal method call
+}
+
+// uncommonType is present only for defined types or types with methods
+// (if T is a defined type, the uncommonTypes for T and *T have methods).
+// Using a pointer to this struct reduces the overall size required
+// to describe a non-defined type with no methods.
+type uncommonType struct {
+	pkgPath nameOff // import path; empty for built-in types like int, string
+	mcount  uint16  // number of methods
+	xcount  uint16  // number of exported methods
+	moff    uint32  // offset from this uncommontype to [mcount]method
+	_       uint32  // unused
+}
+
+// chanDir represents a channel type's direction.
+type chanDir int
+
+const (
+	recvDir chanDir             = 1 << iota // <-chan
+	sendDir                                 // chan<-
+	bothDir = recvDir | sendDir             // chan
+)
+
+// arrayType represents a fixed array type.
+type arrayType struct {
+	rtype
+	elem  *rtype // array element type
+	slice *rtype // slice type
+	len   uintptr
+}
+
+// chanType represents a channel type.
+type chanType struct {
+	rtype
+	elem *rtype  // channel element type
+	dir  uintptr // channel direction (chanDir)
+}
+
+// funcType represents a function type.
+//
+// A *rtype for each in and out parameter is stored in an array that
+// directly follows the funcType (and possibly its uncommonType). So
+// a function type with one method, one input, and one output is:
+//
+//	struct {
+//		funcType
+//		uncommonType
+//		[2]*rtype    // [0] is in, [1] is out
+//	}
+type funcType struct {
+	rtype
+	inCount  uint16
+	outCount uint16 // top bit is set if last input parameter is ...
+}
+
+// imethod represents a method on an interface type
+type imethod struct {
+	name nameOff // name of method
+	typ  typeOff // .(*FuncType) underneath
+}
+
+// interfaceType represents an interface type.
+type interfaceType struct {
+	rtype
+	pkgPath name      // import path
+	methods []imethod // sorted by hash
+}
+
+// mapType represents a map type.
+type mapType struct {
+	rtype
+	key    *rtype // map key type
+	elem   *rtype // map element (value) type
+	bucket *rtype // internal bucket structure
+	// function for hashing keys (ptr to key, seed) -> hash
+	hasher     func(unsafe.Pointer, uintptr) uintptr
+	keysize    uint8  // size of key slot
+	valuesize  uint8  // size of value slot
+	bucketsize uint16 // size of bucket
+	flags      uint32
+}
+
+// ptrType represents a pointer type.
+type ptrType struct {
+	rtype
+	elem *rtype // pointer element (pointed at) type
+}
+
+// sliceType represents a slice type.
+type sliceType struct {
+	rtype
+	elem *rtype // slice element type
+}
+
+// Struct field
+type structField struct {
+	name   name    // name is always non-empty
+	typ    *rtype  // type of field
+	offset uintptr // byte offset of field
+}
+
+func (f *structField) embedded() bool {
+	return f.name.embedded()
+}
+
+// structType represents a struct type.
+type structType struct {
+	rtype
+	pkgPath name
+	fields  []structField // sorted by offset
+}
+
+// name is an encoded type name with optional extra data.
+//
+// The first byte is a bit field containing:
+//
+//	1<<0 the name is exported
+//	1<<1 tag data follows the name
+//	1<<2 pkgPath nameOff follows the name and tag
+//
+// The next two bytes are the data length:
+//
+//	l := uint16(data[1])<<8 | uint16(data[2])
+//
+// Bytes [3:3+l] are the string data.
+//
+// If tag data follows then bytes 3+l and 3+l+1 are the tag length,
+// with the data following.
+//
+// If the import path follows, then 4 bytes at the end of
+// the data form a nameOff. The import path is only set for concrete
+// methods that are defined in a different package than their type.
+//
+// If a name starts with "*", then the exported bit represents
+// whether the pointed to type is exported.
+type name struct {
+	bytes *byte
+}
+
+func (n name) data(off int, whySafe string) *byte {
+	return (*byte)(add(unsafe.Pointer(n.bytes), uintptr(off), whySafe))
+}
+
+func (n name) isExported() bool {
+	return (*n.bytes)&(1<<0) != 0
+}
+
+func (n name) hasTag() bool {
+	return (*n.bytes)&(1<<1) != 0
+}
+
+func (n name) embedded() bool {
+	return (*n.bytes)&(1<<3) != 0
+}
+
+// readVarint parses a varint as encoded by encoding/binary.
+// It returns the number of encoded bytes and the encoded value.
+func (n name) readVarint(off int) (int, int) {
+	v := 0
+	for i := 0; ; i++ {
+		x := *n.data(off+i, "read varint")
+		v += int(x&0x7f) << (7 * i)
+		if x&0x80 == 0 {
+			return i + 1, v
+		}
+	}
+}
+
+func (n name) name() string {
+	if n.bytes == nil {
+		return ""
+	}
+	i, l := n.readVarint(1)
+	return unsafe.String(n.data(1+i, "non-empty string"), l)
+}
+
+func (n name) tag() string {
+	if !n.hasTag() {
+		return ""
+	}
+	i, l := n.readVarint(1)
+	i2, l2 := n.readVarint(1 + i + l)
+	return unsafe.String(n.data(1+i+l+i2, "non-empty string"), l2)
+}
+
+func (n name) pkgPath() string {
+	if n.bytes == nil || *n.data(0, "name flag field")&(1<<2) == 0 {
+		return ""
+	}
+	i, l := n.readVarint(1)
+	off := 1 + i + l
+	if n.hasTag() {
+		i2, l2 := n.readVarint(off)
+		off += i2 + l2
+	}
+	var nameOff int32
+	// Note that this field may not be aligned in memory,
+	// so we cannot use a direct int32 assignment here.
+	copy((*[4]byte)(unsafe.Pointer(&nameOff))[:], (*[4]byte)(unsafe.Pointer(n.data(off, "name offset field")))[:])
+	pkgPathName := name{(*byte)(resolveTypeOff(unsafe.Pointer(n.bytes), nameOff))}
+	return pkgPathName.name()
+}
+
+/*
+ * The compiler knows the exact layout of all the data structures above.
+ * The compiler does not know about the data structures and methods below.
+ */
+
+const (
+	kindDirectIface = 1 << 5
+	kindGCProg      = 1 << 6 // Type.gc points to GC program
+	kindMask        = (1 << 5) - 1
+)
+
+// String returns the name of k.
+func (k Kind) String() string {
+	if int(k) < len(kindNames) {
+		return kindNames[k]
+	}
+	return kindNames[0]
+}
+
+var kindNames = []string{
+	Invalid:       "invalid",
+	Bool:          "bool",
+	Int:           "int",
+	Int8:          "int8",
+	Int16:         "int16",
+	Int32:         "int32",
+	Int64:         "int64",
+	Uint:          "uint",
+	Uint8:         "uint8",
+	Uint16:        "uint16",
+	Uint32:        "uint32",
+	Uint64:        "uint64",
+	Uintptr:       "uintptr",
+	Float32:       "float32",
+	Float64:       "float64",
+	Complex64:     "complex64",
+	Complex128:    "complex128",
+	Array:         "array",
+	Chan:          "chan",
+	Func:          "func",
+	Interface:     "interface",
+	Map:           "map",
+	Ptr:           "ptr",
+	Slice:         "slice",
+	String:        "string",
+	Struct:        "struct",
+	UnsafePointer: "unsafe.Pointer",
+}
+
+func (t *uncommonType) methods() []method {
+	if t.mcount == 0 {
+		return nil
+	}
+	return (*[1 << 16]method)(add(unsafe.Pointer(t), uintptr(t.moff), "t.mcount > 0"))[:t.mcount:t.mcount]
+}
+
+func (t *uncommonType) exportedMethods() []method {
+	if t.xcount == 0 {
+		return nil
+	}
+	return (*[1 << 16]method)(add(unsafe.Pointer(t), uintptr(t.moff), "t.xcount > 0"))[:t.xcount:t.xcount]
+}
+
+// resolveNameOff resolves a name offset from a base pointer.
+// The (*rtype).nameOff method is a convenience wrapper for this function.
+// Implemented in the runtime package.
+func resolveNameOff(ptrInModule unsafe.Pointer, off int32) unsafe.Pointer
+
+// resolveTypeOff resolves an *rtype offset from a base type.
+// The (*rtype).typeOff method is a convenience wrapper for this function.
+// Implemented in the runtime package.
+func resolveTypeOff(rtype unsafe.Pointer, off int32) unsafe.Pointer
+
+type nameOff int32 // offset to a name
+type typeOff int32 // offset to an *rtype
+type textOff int32 // offset from top of text section
+
+func (t *rtype) nameOff(off nameOff) name {
+	return name{(*byte)(resolveNameOff(unsafe.Pointer(t), int32(off)))}
+}
+
+func (t *rtype) typeOff(off typeOff) *rtype {
+	return (*rtype)(resolveTypeOff(unsafe.Pointer(t), int32(off)))
+}
+
+func (t *rtype) uncommon() *uncommonType {
+	if t.tflag&tflagUncommon == 0 {
+		return nil
+	}
+	switch t.Kind() {
+	case Struct:
+		return &(*structTypeUncommon)(unsafe.Pointer(t)).u
+	case Ptr:
+		type u struct {
+			ptrType
+			u uncommonType
+		}
+		return &(*u)(unsafe.Pointer(t)).u
+	case Func:
+		type u struct {
+			funcType
+			u uncommonType
+		}
+		return &(*u)(unsafe.Pointer(t)).u
+	case Slice:
+		type u struct {
+			sliceType
+			u uncommonType
+		}
+		return &(*u)(unsafe.Pointer(t)).u
+	case Array:
+		type u struct {
+			arrayType
+			u uncommonType
+		}
+		return &(*u)(unsafe.Pointer(t)).u
+	case Chan:
+		type u struct {
+			chanType
+			u uncommonType
+		}
+		return &(*u)(unsafe.Pointer(t)).u
+	case Map:
+		type u struct {
+			mapType
+			u uncommonType
+		}
+		return &(*u)(unsafe.Pointer(t)).u
+	case Interface:
+		type u struct {
+			interfaceType
+			u uncommonType
+		}
+		return &(*u)(unsafe.Pointer(t)).u
+	default:
+		type u struct {
+			rtype
+			u uncommonType
+		}
+		return &(*u)(unsafe.Pointer(t)).u
+	}
+}
+
+func (t *rtype) String() string {
+	s := t.nameOff(t.str).name()
+	if t.tflag&tflagExtraStar != 0 {
+		return s[1:]
+	}
+	return s
+}
+
+func (t *rtype) Size() uintptr { return t.size }
+
+func (t *rtype) Kind() Kind { return Kind(t.kind & kindMask) }
+
+func (t *rtype) pointers() bool { return t.ptrdata != 0 }
+
+func (t *rtype) common() *rtype { return t }
+
+func (t *rtype) exportedMethods() []method {
+	ut := t.uncommon()
+	if ut == nil {
+		return nil
+	}
+	return ut.exportedMethods()
+}
+
+func (t *rtype) NumMethod() int {
+	if t.Kind() == Interface {
+		tt := (*interfaceType)(unsafe.Pointer(t))
+		return tt.NumMethod()
+	}
+	return len(t.exportedMethods())
+}
+
+func (t *rtype) PkgPath() string {
+	if t.tflag&tflagNamed == 0 {
+		return ""
+	}
+	ut := t.uncommon()
+	if ut == nil {
+		return ""
+	}
+	return t.nameOff(ut.pkgPath).name()
+}
+
+func (t *rtype) hasName() bool {
+	return t.tflag&tflagNamed != 0
+}
+
+func (t *rtype) Name() string {
+	if !t.hasName() {
+		return ""
+	}
+	s := t.String()
+	i := len(s) - 1
+	sqBrackets := 0
+	for i >= 0 && (s[i] != '.' || sqBrackets != 0) {
+		switch s[i] {
+		case ']':
+			sqBrackets++
+		case '[':
+			sqBrackets--
+		}
+		i--
+	}
+	return s[i+1:]
+}
+
+func (t *rtype) chanDir() chanDir {
+	if t.Kind() != Chan {
+		panic("reflect: chanDir of non-chan type")
+	}
+	tt := (*chanType)(unsafe.Pointer(t))
+	return chanDir(tt.dir)
+}
+
+func (t *rtype) Elem() Type {
+	switch t.Kind() {
+	case Array:
+		tt := (*arrayType)(unsafe.Pointer(t))
+		return toType(tt.elem)
+	case Chan:
+		tt := (*chanType)(unsafe.Pointer(t))
+		return toType(tt.elem)
+	case Map:
+		tt := (*mapType)(unsafe.Pointer(t))
+		return toType(tt.elem)
+	case Ptr:
+		tt := (*ptrType)(unsafe.Pointer(t))
+		return toType(tt.elem)
+	case Slice:
+		tt := (*sliceType)(unsafe.Pointer(t))
+		return toType(tt.elem)
+	}
+	panic("reflect: Elem of invalid type")
+}
+
+func (t *rtype) In(i int) Type {
+	if t.Kind() != Func {
+		panic("reflect: In of non-func type")
+	}
+	tt := (*funcType)(unsafe.Pointer(t))
+	return toType(tt.in()[i])
+}
+
+func (t *rtype) Key() Type {
+	if t.Kind() != Map {
+		panic("reflect: Key of non-map type")
+	}
+	tt := (*mapType)(unsafe.Pointer(t))
+	return toType(tt.key)
+}
+
+func (t *rtype) Len() int {
+	if t.Kind() != Array {
+		panic("reflect: Len of non-array type")
+	}
+	tt := (*arrayType)(unsafe.Pointer(t))
+	return int(tt.len)
+}
+
+func (t *rtype) NumField() int {
+	if t.Kind() != Struct {
+		panic("reflect: NumField of non-struct type")
+	}
+	tt := (*structType)(unsafe.Pointer(t))
+	return len(tt.fields)
+}
+
+func (t *rtype) NumIn() int {
+	if t.Kind() != Func {
+		panic("reflect: NumIn of non-func type")
+	}
+	tt := (*funcType)(unsafe.Pointer(t))
+	return int(tt.inCount)
+}
+
+func (t *rtype) NumOut() int {
+	if t.Kind() != Func {
+		panic("reflect: NumOut of non-func type")
+	}
+	tt := (*funcType)(unsafe.Pointer(t))
+	return len(tt.out())
+}
+
+func (t *rtype) Out(i int) Type {
+	if t.Kind() != Func {
+		panic("reflect: Out of non-func type")
+	}
+	tt := (*funcType)(unsafe.Pointer(t))
+	return toType(tt.out()[i])
+}
+
+func (t *funcType) in() []*rtype {
+	uadd := unsafe.Sizeof(*t)
+	if t.tflag&tflagUncommon != 0 {
+		uadd += unsafe.Sizeof(uncommonType{})
+	}
+	if t.inCount == 0 {
+		return nil
+	}
+	return (*[1 << 20]*rtype)(add(unsafe.Pointer(t), uadd, "t.inCount > 0"))[:t.inCount:t.inCount]
+}
+
+func (t *funcType) out() []*rtype {
+	uadd := unsafe.Sizeof(*t)
+	if t.tflag&tflagUncommon != 0 {
+		uadd += unsafe.Sizeof(uncommonType{})
+	}
+	outCount := t.outCount & (1<<15 - 1)
+	if outCount == 0 {
+		return nil
+	}
+	return (*[1 << 20]*rtype)(add(unsafe.Pointer(t), uadd, "outCount > 0"))[t.inCount : t.inCount+outCount : t.inCount+outCount]
+}
+
+// add returns p+x.
+//
+// The whySafe string is ignored, so that the function still inlines
+// as efficiently as p+x, but all call sites should use the string to
+// record why the addition is safe, which is to say why the addition
+// does not cause x to advance to the very end of p's allocation
+// and therefore point incorrectly at the next block in memory.
+func add(p unsafe.Pointer, x uintptr, whySafe string) unsafe.Pointer {
+	return unsafe.Pointer(uintptr(p) + x)
+}
+
+// NumMethod returns the number of interface methods in the type's method set.
+func (t *interfaceType) NumMethod() int { return len(t.methods) }
+
+// TypeOf returns the reflection Type that represents the dynamic type of i.
+// If i is a nil interface value, TypeOf returns nil.
+func TypeOf(i any) Type {
+	eface := *(*emptyInterface)(unsafe.Pointer(&i))
+	return toType(eface.typ)
+}
+
+func (t *rtype) Implements(u Type) bool {
+	if u == nil {
+		panic("reflect: nil type passed to Type.Implements")
+	}
+	if u.Kind() != Interface {
+		panic("reflect: non-interface type passed to Type.Implements")
+	}
+	return implements(u.(*rtype), t)
+}
+
+func (t *rtype) AssignableTo(u Type) bool {
+	if u == nil {
+		panic("reflect: nil type passed to Type.AssignableTo")
+	}
+	uu := u.(*rtype)
+	return directlyAssignable(uu, t) || implements(uu, t)
+}
+
+func (t *rtype) Comparable() bool {
+	return t.equal != nil
+}
+
+// implements reports whether the type V implements the interface type T.
+func implements(T, V *rtype) bool {
+	if T.Kind() != Interface {
+		return false
+	}
+	t := (*interfaceType)(unsafe.Pointer(T))
+	if len(t.methods) == 0 {
+		return true
+	}
+
+	// The same algorithm applies in both cases, but the
+	// method tables for an interface type and a concrete type
+	// are different, so the code is duplicated.
+	// In both cases the algorithm is a linear scan over the two
+	// lists - T's methods and V's methods - simultaneously.
+	// Since method tables are stored in a unique sorted order
+	// (alphabetical, with no duplicate method names), the scan
+	// through V's methods must hit a match for each of T's
+	// methods along the way, or else V does not implement T.
+	// This lets us run the scan in overall linear time instead of
+	// the quadratic time  a naive search would require.
+	// See also ../runtime/iface.go.
+	if V.Kind() == Interface {
+		v := (*interfaceType)(unsafe.Pointer(V))
+		i := 0
+		for j := 0; j < len(v.methods); j++ {
+			tm := &t.methods[i]
+			tmName := t.nameOff(tm.name)
+			vm := &v.methods[j]
+			vmName := V.nameOff(vm.name)
+			if vmName.name() == tmName.name() && V.typeOff(vm.typ) == t.typeOff(tm.typ) {
+				if !tmName.isExported() {
+					tmPkgPath := tmName.pkgPath()
+					if tmPkgPath == "" {
+						tmPkgPath = t.pkgPath.name()
+					}
+					vmPkgPath := vmName.pkgPath()
+					if vmPkgPath == "" {
+						vmPkgPath = v.pkgPath.name()
+					}
+					if tmPkgPath != vmPkgPath {
+						continue
+					}
+				}
+				if i++; i >= len(t.methods) {
+					return true
+				}
+			}
+		}
+		return false
+	}
+
+	v := V.uncommon()
+	if v == nil {
+		return false
+	}
+	i := 0
+	vmethods := v.methods()
+	for j := 0; j < int(v.mcount); j++ {
+		tm := &t.methods[i]
+		tmName := t.nameOff(tm.name)
+		vm := vmethods[j]
+		vmName := V.nameOff(vm.name)
+		if vmName.name() == tmName.name() && V.typeOff(vm.mtyp) == t.typeOff(tm.typ) {
+			if !tmName.isExported() {
+				tmPkgPath := tmName.pkgPath()
+				if tmPkgPath == "" {
+					tmPkgPath = t.pkgPath.name()
+				}
+				vmPkgPath := vmName.pkgPath()
+				if vmPkgPath == "" {
+					vmPkgPath = V.nameOff(v.pkgPath).name()
+				}
+				if tmPkgPath != vmPkgPath {
+					continue
+				}
+			}
+			if i++; i >= len(t.methods) {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+// directlyAssignable reports whether a value x of type V can be directly
+// assigned (using memmove) to a value of type T.
+// https://golang.org/doc/go_spec.html#Assignability
+// Ignoring the interface rules (implemented elsewhere)
+// and the ideal constant rules (no ideal constants at run time).
+func directlyAssignable(T, V *rtype) bool {
+	// x's type V is identical to T?
+	if T == V {
+		return true
+	}
+
+	// Otherwise at least one of T and V must not be defined
+	// and they must have the same kind.
+	if T.hasName() && V.hasName() || T.Kind() != V.Kind() {
+		return false
+	}
+
+	// x's type T and V must  have identical underlying types.
+	return haveIdenticalUnderlyingType(T, V, true)
+}
+
+func haveIdenticalType(T, V Type, cmpTags bool) bool {
+	if cmpTags {
+		return T == V
+	}
+
+	if T.Name() != V.Name() || T.Kind() != V.Kind() {
+		return false
+	}
+
+	return haveIdenticalUnderlyingType(T.common(), V.common(), false)
+}
+
+func haveIdenticalUnderlyingType(T, V *rtype, cmpTags bool) bool {
+	if T == V {
+		return true
+	}
+
+	kind := T.Kind()
+	if kind != V.Kind() {
+		return false
+	}
+
+	// Non-composite types of equal kind have same underlying type
+	// (the predefined instance of the type).
+	if Bool <= kind && kind <= Complex128 || kind == String || kind == UnsafePointer {
+		return true
+	}
+
+	// Composite types.
+	switch kind {
+	case Array:
+		return T.Len() == V.Len() && haveIdenticalType(T.Elem(), V.Elem(), cmpTags)
+
+	case Chan:
+		// Special case:
+		// x is a bidirectional channel value, T is a channel type,
+		// and x's type V and T have identical element types.
+		if V.chanDir() == bothDir && haveIdenticalType(T.Elem(), V.Elem(), cmpTags) {
+			return true
+		}
+
+		// Otherwise continue test for identical underlying type.
+		return V.chanDir() == T.chanDir() && haveIdenticalType(T.Elem(), V.Elem(), cmpTags)
+
+	case Func:
+		t := (*funcType)(unsafe.Pointer(T))
+		v := (*funcType)(unsafe.Pointer(V))
+		if t.outCount != v.outCount || t.inCount != v.inCount {
+			return false
+		}
+		for i := 0; i < t.NumIn(); i++ {
+			if !haveIdenticalType(t.In(i), v.In(i), cmpTags) {
+				return false
+			}
+		}
+		for i := 0; i < t.NumOut(); i++ {
+			if !haveIdenticalType(t.Out(i), v.Out(i), cmpTags) {
+				return false
+			}
+		}
+		return true
+
+	case Interface:
+		t := (*interfaceType)(unsafe.Pointer(T))
+		v := (*interfaceType)(unsafe.Pointer(V))
+		if len(t.methods) == 0 && len(v.methods) == 0 {
+			return true
+		}
+		// Might have the same methods but still
+		// need a run time conversion.
+		return false
+
+	case Map:
+		return haveIdenticalType(T.Key(), V.Key(), cmpTags) && haveIdenticalType(T.Elem(), V.Elem(), cmpTags)
+
+	case Ptr, Slice:
+		return haveIdenticalType(T.Elem(), V.Elem(), cmpTags)
+
+	case Struct:
+		t := (*structType)(unsafe.Pointer(T))
+		v := (*structType)(unsafe.Pointer(V))
+		if len(t.fields) != len(v.fields) {
+			return false
+		}
+		if t.pkgPath.name() != v.pkgPath.name() {
+			return false
+		}
+		for i := range t.fields {
+			tf := &t.fields[i]
+			vf := &v.fields[i]
+			if tf.name.name() != vf.name.name() {
+				return false
+			}
+			if !haveIdenticalType(tf.typ, vf.typ, cmpTags) {
+				return false
+			}
+			if cmpTags && tf.name.tag() != vf.name.tag() {
+				return false
+			}
+			if tf.offset != vf.offset {
+				return false
+			}
+			if tf.embedded() != vf.embedded() {
+				return false
+			}
+		}
+		return true
+	}
+
+	return false
+}
+
+type structTypeUncommon struct {
+	structType
+	u uncommonType
+}
+
+// toType converts from a *rtype to a Type that can be returned
+// to the client of package reflect. In gc, the only concern is that
+// a nil *rtype must be replaced by a nil Type, but in gccgo this
+// function takes care of ensuring that multiple *rtype for the same
+// type are coalesced into a single Type.
+func toType(t *rtype) Type {
+	if t == nil {
+		return nil
+	}
+	return t
+}
+
+// ifaceIndir reports whether t is stored indirectly in an interface value.
+func ifaceIndir(t *rtype) bool {
+	return t.kind&kindDirectIface == 0
+}
diff --git a/contrib/go/_std_1.20/src/internal/reflectlite/value.go b/contrib/go/_std_1.20/src/internal/reflectlite/value.go
new file mode 100644
index 0000000000..b9bca3ab44
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/reflectlite/value.go
@@ -0,0 +1,477 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package reflectlite
+
+import (
+	"internal/goarch"
+	"internal/unsafeheader"
+	"runtime"
+	"unsafe"
+)
+
+// Value is the reflection interface to a Go value.
+//
+// Not all methods apply to all kinds of values. Restrictions,
+// if any, are noted in the documentation for each method.
+// Use the Kind method to find out the kind of value before
+// calling kind-specific methods. Calling a method
+// inappropriate to the kind of type causes a run time panic.
+//
+// The zero Value represents no value.
+// Its IsValid method returns false, its Kind method returns Invalid,
+// its String method returns "<invalid Value>", and all other methods panic.
+// Most functions and methods never return an invalid value.
+// If one does, its documentation states the conditions explicitly.
+//
+// A Value can be used concurrently by multiple goroutines provided that
+// the underlying Go value can be used concurrently for the equivalent
+// direct operations.
+//
+// To compare two Values, compare the results of the Interface method.
+// Using == on two Values does not compare the underlying values
+// they represent.
+type Value struct {
+	// typ holds the type of the value represented by a Value.
+	typ *rtype
+
+	// Pointer-valued data or, if flagIndir is set, pointer to data.
+	// Valid when either flagIndir is set or typ.pointers() is true.
+	ptr unsafe.Pointer
+
+	// flag holds metadata about the value.
+	// The lowest bits are flag bits:
+	//	- flagStickyRO: obtained via unexported not embedded field, so read-only
+	//	- flagEmbedRO: obtained via unexported embedded field, so read-only
+	//	- flagIndir: val holds a pointer to the data
+	//	- flagAddr: v.CanAddr is true (implies flagIndir)
+	// Value cannot represent method values.
+	// The next five bits give the Kind of the value.
+	// This repeats typ.Kind() except for method values.
+	// The remaining 23+ bits give a method number for method values.
+	// If flag.kind() != Func, code can assume that flagMethod is unset.
+	// If ifaceIndir(typ), code can assume that flagIndir is set.
+	flag
+
+	// A method value represents a curried method invocation
+	// like r.Read for some receiver r. The typ+val+flag bits describe
+	// the receiver r, but the flag's Kind bits say Func (methods are
+	// functions), and the top bits of the flag give the method number
+	// in r's type's method table.
+}
+
+type flag uintptr
+
+const (
+	flagKindWidth        = 5 // there are 27 kinds
+	flagKindMask    flag = 1<<flagKindWidth - 1
+	flagStickyRO    flag = 1 << 5
+	flagEmbedRO     flag = 1 << 6
+	flagIndir       flag = 1 << 7
+	flagAddr        flag = 1 << 8
+	flagMethod      flag = 1 << 9
+	flagMethodShift      = 10
+	flagRO          flag = flagStickyRO | flagEmbedRO
+)
+
+func (f flag) kind() Kind {
+	return Kind(f & flagKindMask)
+}
+
+func (f flag) ro() flag {
+	if f&flagRO != 0 {
+		return flagStickyRO
+	}
+	return 0
+}
+
+// pointer returns the underlying pointer represented by v.
+// v.Kind() must be Pointer, Map, Chan, Func, or UnsafePointer
+func (v Value) pointer() unsafe.Pointer {
+	if v.typ.size != goarch.PtrSize || !v.typ.pointers() {
+		panic("can't call pointer on a non-pointer Value")
+	}
+	if v.flag&flagIndir != 0 {
+		return *(*unsafe.Pointer)(v.ptr)
+	}
+	return v.ptr
+}
+
+// packEface converts v to the empty interface.
+func packEface(v Value) any {
+	t := v.typ
+	var i any
+	e := (*emptyInterface)(unsafe.Pointer(&i))
+	// First, fill in the data portion of the interface.
+	switch {
+	case ifaceIndir(t):
+		if v.flag&flagIndir == 0 {
+			panic("bad indir")
+		}
+		// Value is indirect, and so is the interface we're making.
+		ptr := v.ptr
+		if v.flag&flagAddr != 0 {
+			// TODO: pass safe boolean from valueInterface so
+			// we don't need to copy if safe==true?
+			c := unsafe_New(t)
+			typedmemmove(t, c, ptr)
+			ptr = c
+		}
+		e.word = ptr
+	case v.flag&flagIndir != 0:
+		// Value is indirect, but interface is direct. We need
+		// to load the data at v.ptr into the interface data word.
+		e.word = *(*unsafe.Pointer)(v.ptr)
+	default:
+		// Value is direct, and so is the interface.
+		e.word = v.ptr
+	}
+	// Now, fill in the type portion. We're very careful here not
+	// to have any operation between the e.word and e.typ assignments
+	// that would let the garbage collector observe the partially-built
+	// interface value.
+	e.typ = t
+	return i
+}
+
+// unpackEface converts the empty interface i to a Value.
+func unpackEface(i any) Value {
+	e := (*emptyInterface)(unsafe.Pointer(&i))
+	// NOTE: don't read e.word until we know whether it is really a pointer or not.
+	t := e.typ
+	if t == nil {
+		return Value{}
+	}
+	f := flag(t.Kind())
+	if ifaceIndir(t) {
+		f |= flagIndir
+	}
+	return Value{t, e.word, f}
+}
+
+// A ValueError occurs when a Value method is invoked on
+// a Value that does not support it. Such cases are documented
+// in the description of each method.
+type ValueError struct {
+	Method string
+	Kind   Kind
+}
+
+func (e *ValueError) Error() string {
+	if e.Kind == 0 {
+		return "reflect: call of " + e.Method + " on zero Value"
+	}
+	return "reflect: call of " + e.Method + " on " + e.Kind.String() + " Value"
+}
+
+// methodName returns the name of the calling method,
+// assumed to be two stack frames above.
+func methodName() string {
+	pc, _, _, _ := runtime.Caller(2)
+	f := runtime.FuncForPC(pc)
+	if f == nil {
+		return "unknown method"
+	}
+	return f.Name()
+}
+
+// emptyInterface is the header for an interface{} value.
+type emptyInterface struct {
+	typ  *rtype
+	word unsafe.Pointer
+}
+
+// mustBeExported panics if f records that the value was obtained using
+// an unexported field.
+func (f flag) mustBeExported() {
+	if f == 0 {
+		panic(&ValueError{methodName(), 0})
+	}
+	if f&flagRO != 0 {
+		panic("reflect: " + methodName() + " using value obtained using unexported field")
+	}
+}
+
+// mustBeAssignable panics if f records that the value is not assignable,
+// which is to say that either it was obtained using an unexported field
+// or it is not addressable.
+func (f flag) mustBeAssignable() {
+	if f == 0 {
+		panic(&ValueError{methodName(), Invalid})
+	}
+	// Assignable if addressable and not read-only.
+	if f&flagRO != 0 {
+		panic("reflect: " + methodName() + " using value obtained using unexported field")
+	}
+	if f&flagAddr == 0 {
+		panic("reflect: " + methodName() + " using unaddressable value")
+	}
+}
+
+// CanSet reports whether the value of v can be changed.
+// A Value can be changed only if it is addressable and was not
+// obtained by the use of unexported struct fields.
+// If CanSet returns false, calling Set or any type-specific
+// setter (e.g., SetBool, SetInt) will panic.
+func (v Value) CanSet() bool {
+	return v.flag&(flagAddr|flagRO) == flagAddr
+}
+
+// Elem returns the value that the interface v contains
+// or that the pointer v points to.
+// It panics if v's Kind is not Interface or Pointer.
+// It returns the zero Value if v is nil.
+func (v Value) Elem() Value {
+	k := v.kind()
+	switch k {
+	case Interface:
+		var eface any
+		if v.typ.NumMethod() == 0 {
+			eface = *(*any)(v.ptr)
+		} else {
+			eface = (any)(*(*interface {
+				M()
+			})(v.ptr))
+		}
+		x := unpackEface(eface)
+		if x.flag != 0 {
+			x.flag |= v.flag.ro()
+		}
+		return x
+	case Pointer:
+		ptr := v.ptr
+		if v.flag&flagIndir != 0 {
+			ptr = *(*unsafe.Pointer)(ptr)
+		}
+		// The returned value's address is v's value.
+		if ptr == nil {
+			return Value{}
+		}
+		tt := (*ptrType)(unsafe.Pointer(v.typ))
+		typ := tt.elem
+		fl := v.flag&flagRO | flagIndir | flagAddr
+		fl |= flag(typ.Kind())
+		return Value{typ, ptr, fl}
+	}
+	panic(&ValueError{"reflectlite.Value.Elem", v.kind()})
+}
+
+func valueInterface(v Value) any {
+	if v.flag == 0 {
+		panic(&ValueError{"reflectlite.Value.Interface", 0})
+	}
+
+	if v.kind() == Interface {
+		// Special case: return the element inside the interface.
+		// Empty interface has one layout, all interfaces with
+		// methods have a second layout.
+		if v.numMethod() == 0 {
+			return *(*any)(v.ptr)
+		}
+		return *(*interface {
+			M()
+		})(v.ptr)
+	}
+
+	// TODO: pass safe to packEface so we don't need to copy if safe==true?
+	return packEface(v)
+}
+
+// IsNil reports whether its argument v is nil. The argument must be
+// a chan, func, interface, map, pointer, or slice value; if it is
+// not, IsNil panics. Note that IsNil is not always equivalent to a
+// regular comparison with nil in Go. For example, if v was created
+// by calling ValueOf with an uninitialized interface variable i,
+// i==nil will be true but v.IsNil will panic as v will be the zero
+// Value.
+func (v Value) IsNil() bool {
+	k := v.kind()
+	switch k {
+	case Chan, Func, Map, Pointer, UnsafePointer:
+		// if v.flag&flagMethod != 0 {
+		// 	return false
+		// }
+		ptr := v.ptr
+		if v.flag&flagIndir != 0 {
+			ptr = *(*unsafe.Pointer)(ptr)
+		}
+		return ptr == nil
+	case Interface, Slice:
+		// Both interface and slice are nil if first word is 0.
+		// Both are always bigger than a word; assume flagIndir.
+		return *(*unsafe.Pointer)(v.ptr) == nil
+	}
+	panic(&ValueError{"reflectlite.Value.IsNil", v.kind()})
+}
+
+// IsValid reports whether v represents a value.
+// It returns false if v is the zero Value.
+// If IsValid returns false, all other methods except String panic.
+// Most functions and methods never return an invalid Value.
+// If one does, its documentation states the conditions explicitly.
+func (v Value) IsValid() bool {
+	return v.flag != 0
+}
+
+// Kind returns v's Kind.
+// If v is the zero Value (IsValid returns false), Kind returns Invalid.
+func (v Value) Kind() Kind {
+	return v.kind()
+}
+
+// implemented in runtime:
+func chanlen(unsafe.Pointer) int
+func maplen(unsafe.Pointer) int
+
+// Len returns v's length.
+// It panics if v's Kind is not Array, Chan, Map, Slice, or String.
+func (v Value) Len() int {
+	k := v.kind()
+	switch k {
+	case Array:
+		tt := (*arrayType)(unsafe.Pointer(v.typ))
+		return int(tt.len)
+	case Chan:
+		return chanlen(v.pointer())
+	case Map:
+		return maplen(v.pointer())
+	case Slice:
+		// Slice is bigger than a word; assume flagIndir.
+		return (*unsafeheader.Slice)(v.ptr).Len
+	case String:
+		// String is bigger than a word; assume flagIndir.
+		return (*unsafeheader.String)(v.ptr).Len
+	}
+	panic(&ValueError{"reflect.Value.Len", v.kind()})
+}
+
+// NumMethod returns the number of exported methods in the value's method set.
+func (v Value) numMethod() int {
+	if v.typ == nil {
+		panic(&ValueError{"reflectlite.Value.NumMethod", Invalid})
+	}
+	return v.typ.NumMethod()
+}
+
+// Set assigns x to the value v.
+// It panics if CanSet returns false.
+// As in Go, x's value must be assignable to v's type.
+func (v Value) Set(x Value) {
+	v.mustBeAssignable()
+	x.mustBeExported() // do not let unexported x leak
+	var target unsafe.Pointer
+	if v.kind() == Interface {
+		target = v.ptr
+	}
+	x = x.assignTo("reflectlite.Set", v.typ, target)
+	if x.flag&flagIndir != 0 {
+		typedmemmove(v.typ, v.ptr, x.ptr)
+	} else {
+		*(*unsafe.Pointer)(v.ptr) = x.ptr
+	}
+}
+
+// Type returns v's type.
+func (v Value) Type() Type {
+	f := v.flag
+	if f == 0 {
+		panic(&ValueError{"reflectlite.Value.Type", Invalid})
+	}
+	// Method values not supported.
+	return v.typ
+}
+
+/*
+ * constructors
+ */
+
+// implemented in package runtime
+func unsafe_New(*rtype) unsafe.Pointer
+
+// ValueOf returns a new Value initialized to the concrete value
+// stored in the interface i. ValueOf(nil) returns the zero Value.
+func ValueOf(i any) Value {
+	if i == nil {
+		return Value{}
+	}
+
+	// TODO: Maybe allow contents of a Value to live on the stack.
+	// For now we make the contents always escape to the heap. It
+	// makes life easier in a few places (see chanrecv/mapassign
+	// comment below).
+	escapes(i)
+
+	return unpackEface(i)
+}
+
+// assignTo returns a value v that can be assigned directly to typ.
+// It panics if v is not assignable to typ.
+// For a conversion to an interface type, target is a suggested scratch space to use.
+func (v Value) assignTo(context string, dst *rtype, target unsafe.Pointer) Value {
+	// if v.flag&flagMethod != 0 {
+	// 	v = makeMethodValue(context, v)
+	// }
+
+	switch {
+	case directlyAssignable(dst, v.typ):
+		// Overwrite type so that they match.
+		// Same memory layout, so no harm done.
+		fl := v.flag&(flagAddr|flagIndir) | v.flag.ro()
+		fl |= flag(dst.Kind())
+		return Value{dst, v.ptr, fl}
+
+	case implements(dst, v.typ):
+		if target == nil {
+			target = unsafe_New(dst)
+		}
+		if v.Kind() == Interface && v.IsNil() {
+			// A nil ReadWriter passed to nil Reader is OK,
+			// but using ifaceE2I below will panic.
+			// Avoid the panic by returning a nil dst (e.g., Reader) explicitly.
+			return Value{dst, nil, flag(Interface)}
+		}
+		x := valueInterface(v)
+		if dst.NumMethod() == 0 {
+			*(*any)(target) = x
+		} else {
+			ifaceE2I(dst, x, target)
+		}
+		return Value{dst, target, flagIndir | flag(Interface)}
+	}
+
+	// Failed.
+	panic(context + ": value of type " + v.typ.String() + " is not assignable to type " + dst.String())
+}
+
+// arrayAt returns the i-th element of p,
+// an array whose elements are eltSize bytes wide.
+// The array pointed at by p must have at least i+1 elements:
+// it is invalid (but impossible to check here) to pass i >= len,
+// because then the result will point outside the array.
+// whySafe must explain why i < len. (Passing "i < len" is fine;
+// the benefit is to surface this assumption at the call site.)
+func arrayAt(p unsafe.Pointer, i int, eltSize uintptr, whySafe string) unsafe.Pointer {
+	return add(p, uintptr(i)*eltSize, "i < len")
+}
+
+func ifaceE2I(t *rtype, src any, dst unsafe.Pointer)
+
+// typedmemmove copies a value of type t to dst from src.
+//
+//go:noescape
+func typedmemmove(t *rtype, dst, src unsafe.Pointer)
+
+// Dummy annotation marking that the value x escapes,
+// for use in cases where the reflect code is so clever that
+// the compiler cannot follow.
+func escapes(x any) {
+	if dummy.b {
+		dummy.x = x
+	}
+}
+
+var dummy struct {
+	b bool
+	x any
+}
diff --git a/contrib/go/_std_1.20/src/internal/reflectlite/ya.make b/contrib/go/_std_1.20/src/internal/reflectlite/ya.make
new file mode 100644
index 0000000000..3747308e12
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/reflectlite/ya.make
@@ -0,0 +1,10 @@
+GO_LIBRARY()
+
+SRCS(
+    asm.s
+    swapper.go
+    type.go
+    value.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/safefilepath/path.go b/contrib/go/_std_1.20/src/internal/safefilepath/path.go
new file mode 100644
index 0000000000..0f0a270c30
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/safefilepath/path.go
@@ -0,0 +1,21 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package safefilepath manipulates operating-system file paths.
+package safefilepath
+
+import (
+	"errors"
+)
+
+var errInvalidPath = errors.New("invalid path")
+
+// FromFS converts a slash-separated path into an operating-system path.
+//
+// FromFS returns an error if the path cannot be represented by the operating
+// system. For example, paths containing '\' and ':' characters are rejected
+// on Windows.
+func FromFS(path string) (string, error) {
+	return fromFS(path)
+}
diff --git a/contrib/go/_std_1.20/src/internal/safefilepath/path_other.go b/contrib/go/_std_1.20/src/internal/safefilepath/path_other.go
new file mode 100644
index 0000000000..974e7751a2
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/safefilepath/path_other.go
@@ -0,0 +1,23 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !windows
+
+package safefilepath
+
+import "runtime"
+
+func fromFS(path string) (string, error) {
+	if runtime.GOOS == "plan9" {
+		if len(path) > 0 && path[0] == '#' {
+			return "", errInvalidPath
+		}
+	}
+	for i := range path {
+		if path[i] == 0 {
+			return "", errInvalidPath
+		}
+	}
+	return path, nil
+}
diff --git a/contrib/go/_std_1.20/src/internal/safefilepath/path_windows.go b/contrib/go/_std_1.20/src/internal/safefilepath/path_windows.go
new file mode 100644
index 0000000000..909c150edc
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/safefilepath/path_windows.go
@@ -0,0 +1,95 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package safefilepath
+
+import (
+	"syscall"
+	"unicode/utf8"
+)
+
+func fromFS(path string) (string, error) {
+	if !utf8.ValidString(path) {
+		return "", errInvalidPath
+	}
+	for len(path) > 1 && path[0] == '/' && path[1] == '/' {
+		path = path[1:]
+	}
+	containsSlash := false
+	for p := path; p != ""; {
+		// Find the next path element.
+		i := 0
+		dot := -1
+		for i < len(p) && p[i] != '/' {
+			switch p[i] {
+			case 0, '\\', ':':
+				return "", errInvalidPath
+			case '.':
+				if dot < 0 {
+					dot = i
+				}
+			}
+			i++
+		}
+		part := p[:i]
+		if i < len(p) {
+			containsSlash = true
+			p = p[i+1:]
+		} else {
+			p = ""
+		}
+		// Trim the extension and look for a reserved name.
+		base := part
+		if dot >= 0 {
+			base = part[:dot]
+		}
+		if isReservedName(base) {
+			if dot < 0 {
+				return "", errInvalidPath
+			}
+			// The path element is a reserved name with an extension.
+			// Some Windows versions consider this a reserved name,
+			// while others do not. Use FullPath to see if the name is
+			// reserved.
+			if p, _ := syscall.FullPath(part); len(p) >= 4 && p[:4] == `\\.\` {
+				return "", errInvalidPath
+			}
+		}
+	}
+	if containsSlash {
+		// We can't depend on strings, so substitute \ for / manually.
+		buf := []byte(path)
+		for i, b := range buf {
+			if b == '/' {
+				buf[i] = '\\'
+			}
+		}
+		path = string(buf)
+	}
+	return path, nil
+}
+
+// isReservedName reports if name is a Windows reserved device name.
+// It does not detect names with an extension, which are also reserved on some Windows versions.
+//
+// For details, search for PRN in
+// https://docs.microsoft.com/en-us/windows/desktop/fileio/naming-a-file.
+func isReservedName(name string) bool {
+	if 3 <= len(name) && len(name) <= 4 {
+		switch string([]byte{toUpper(name[0]), toUpper(name[1]), toUpper(name[2])}) {
+		case "CON", "PRN", "AUX", "NUL":
+			return len(name) == 3
+		case "COM", "LPT":
+			return len(name) == 4 && '1' <= name[3] && name[3] <= '9'
+		}
+	}
+	return false
+}
+
+func toUpper(c byte) byte {
+	if 'a' <= c && c <= 'z' {
+		return c - ('a' - 'A')
+	}
+	return c
+}
diff --git a/contrib/go/_std_1.20/src/internal/safefilepath/ya.make b/contrib/go/_std_1.20/src/internal/safefilepath/ya.make
new file mode 100644
index 0000000000..db2dcfda27
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/safefilepath/ya.make
@@ -0,0 +1,25 @@
+GO_LIBRARY()
+
+SRCS(
+    path.go
+)
+
+IF (OS_DARWIN)
+    SRCS(
+        path_other.go
+    )
+ENDIF()
+
+IF (OS_LINUX)
+    SRCS(
+        path_other.go
+    )
+ENDIF()
+
+IF (OS_WINDOWS)
+    SRCS(
+        path_windows.go
+    )
+ENDIF()
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/saferio/io.go b/contrib/go/_std_1.20/src/internal/saferio/io.go
new file mode 100644
index 0000000000..66cc044c74
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/saferio/io.go
@@ -0,0 +1,135 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package saferio provides I/O functions that avoid allocating large
+// amounts of memory unnecessarily. This is intended for packages that
+// read data from an [io.Reader] where the size is part of the input
+// data but the input may be corrupt, or may be provided by an
+// untrustworthy attacker.
+package saferio
+
+import (
+	"io"
+	"reflect"
+)
+
+// chunk is an arbitrary limit on how much memory we are willing
+// to allocate without concern.
+const chunk = 10 << 20 // 10M
+
+// ReadData reads n bytes from the input stream, but avoids allocating
+// all n bytes if n is large. This avoids crashing the program by
+// allocating all n bytes in cases where n is incorrect.
+//
+// The error is io.EOF only if no bytes were read.
+// If an io.EOF happens after reading some but not all the bytes,
+// ReadData returns io.ErrUnexpectedEOF.
+func ReadData(r io.Reader, n uint64) ([]byte, error) {
+	if int64(n) < 0 || n != uint64(int(n)) {
+		// n is too large to fit in int, so we can't allocate
+		// a buffer large enough. Treat this as a read failure.
+		return nil, io.ErrUnexpectedEOF
+	}
+
+	if n < chunk {
+		buf := make([]byte, n)
+		_, err := io.ReadFull(r, buf)
+		if err != nil {
+			return nil, err
+		}
+		return buf, nil
+	}
+
+	var buf []byte
+	buf1 := make([]byte, chunk)
+	for n > 0 {
+		next := n
+		if next > chunk {
+			next = chunk
+		}
+		_, err := io.ReadFull(r, buf1[:next])
+		if err != nil {
+			if len(buf) > 0 && err == io.EOF {
+				err = io.ErrUnexpectedEOF
+			}
+			return nil, err
+		}
+		buf = append(buf, buf1[:next]...)
+		n -= next
+	}
+	return buf, nil
+}
+
+// ReadDataAt reads n bytes from the input stream at off, but avoids
+// allocating all n bytes if n is large. This avoids crashing the program
+// by allocating all n bytes in cases where n is incorrect.
+func ReadDataAt(r io.ReaderAt, n uint64, off int64) ([]byte, error) {
+	if int64(n) < 0 || n != uint64(int(n)) {
+		// n is too large to fit in int, so we can't allocate
+		// a buffer large enough. Treat this as a read failure.
+		return nil, io.ErrUnexpectedEOF
+	}
+
+	if n < chunk {
+		buf := make([]byte, n)
+		_, err := r.ReadAt(buf, off)
+		if err != nil {
+			// io.SectionReader can return EOF for n == 0,
+			// but for our purposes that is a success.
+			if err != io.EOF || n > 0 {
+				return nil, err
+			}
+		}
+		return buf, nil
+	}
+
+	var buf []byte
+	buf1 := make([]byte, chunk)
+	for n > 0 {
+		next := n
+		if next > chunk {
+			next = chunk
+		}
+		_, err := r.ReadAt(buf1[:next], off)
+		if err != nil {
+			return nil, err
+		}
+		buf = append(buf, buf1[:next]...)
+		n -= next
+		off += int64(next)
+	}
+	return buf, nil
+}
+
+// SliceCap returns the capacity to use when allocating a slice.
+// After the slice is allocated with the capacity, it should be
+// built using append. This will avoid allocating too much memory
+// if the capacity is large and incorrect.
+//
+// A negative result means that the value is always too big.
+//
+// The element type is described by passing a pointer to a value of that type.
+// This would ideally use generics, but this code is built with
+// the bootstrap compiler which need not support generics.
+// We use a pointer so that we can handle slices of interface type.
+func SliceCap(v any, c uint64) int {
+	if int64(c) < 0 || c != uint64(int(c)) {
+		return -1
+	}
+	typ := reflect.TypeOf(v)
+	if typ.Kind() != reflect.Ptr {
+		panic("SliceCap called with non-pointer type")
+	}
+	size := uint64(typ.Elem().Size())
+	if size > 0 && c > (1<<64-1)/size {
+		return -1
+	}
+	if c*size > chunk {
+		c = uint64(chunk / size)
+		if c == 0 {
+			c = 1
+		}
+	}
+	return int(c)
+}
diff --git a/contrib/go/_std_1.20/src/internal/saferio/ya.make b/contrib/go/_std_1.20/src/internal/saferio/ya.make
new file mode 100644
index 0000000000..1773a7384e
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/saferio/ya.make
@@ -0,0 +1,7 @@
+GO_LIBRARY()
+
+SRCS(
+    io.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/singleflight/singleflight.go b/contrib/go/_std_1.20/src/internal/singleflight/singleflight.go
new file mode 100644
index 0000000000..d0e6d2f84a
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/singleflight/singleflight.go
@@ -0,0 +1,123 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package singleflight provides a duplicate function call suppression
+// mechanism.
+package singleflight
+
+import "sync"
+
+// call is an in-flight or completed singleflight.Do call
+type call struct {
+	wg sync.WaitGroup
+
+	// These fields are written once before the WaitGroup is done
+	// and are only read after the WaitGroup is done.
+	val any
+	err error
+
+	// These fields are read and written with the singleflight
+	// mutex held before the WaitGroup is done, and are read but
+	// not written after the WaitGroup is done.
+	dups  int
+	chans []chan<- Result
+}
+
+// Group represents a class of work and forms a namespace in
+// which units of work can be executed with duplicate suppression.
+type Group struct {
+	mu sync.Mutex       // protects m
+	m  map[string]*call // lazily initialized
+}
+
+// Result holds the results of Do, so they can be passed
+// on a channel.
+type Result struct {
+	Val    any
+	Err    error
+	Shared bool
+}
+
+// Do executes and returns the results of the given function, making
+// sure that only one execution is in-flight for a given key at a
+// time. If a duplicate comes in, the duplicate caller waits for the
+// original to complete and receives the same results.
+// The return value shared indicates whether v was given to multiple callers.
+func (g *Group) Do(key string, fn func() (any, error)) (v any, err error, shared bool) {
+	g.mu.Lock()
+	if g.m == nil {
+		g.m = make(map[string]*call)
+	}
+	if c, ok := g.m[key]; ok {
+		c.dups++
+		g.mu.Unlock()
+		c.wg.Wait()
+		return c.val, c.err, true
+	}
+	c := new(call)
+	c.wg.Add(1)
+	g.m[key] = c
+	g.mu.Unlock()
+
+	g.doCall(c, key, fn)
+	return c.val, c.err, c.dups > 0
+}
+
+// DoChan is like Do but returns a channel that will receive the
+// results when they are ready.
+func (g *Group) DoChan(key string, fn func() (any, error)) <-chan Result {
+	ch := make(chan Result, 1)
+	g.mu.Lock()
+	if g.m == nil {
+		g.m = make(map[string]*call)
+	}
+	if c, ok := g.m[key]; ok {
+		c.dups++
+		c.chans = append(c.chans, ch)
+		g.mu.Unlock()
+		return ch
+	}
+	c := &call{chans: []chan<- Result{ch}}
+	c.wg.Add(1)
+	g.m[key] = c
+	g.mu.Unlock()
+
+	go g.doCall(c, key, fn)
+
+	return ch
+}
+
+// doCall handles the single call for a key.
+func (g *Group) doCall(c *call, key string, fn func() (any, error)) {
+	c.val, c.err = fn()
+
+	g.mu.Lock()
+	c.wg.Done()
+	if g.m[key] == c {
+		delete(g.m, key)
+	}
+	for _, ch := range c.chans {
+		ch <- Result{c.val, c.err, c.dups > 0}
+	}
+	g.mu.Unlock()
+}
+
+// ForgetUnshared tells the singleflight to forget about a key if it is not
+// shared with any other goroutines. Future calls to Do for a forgotten key
+// will call the function rather than waiting for an earlier call to complete.
+// Returns whether the key was forgotten or unknown--that is, whether no
+// other goroutines are waiting for the result.
+func (g *Group) ForgetUnshared(key string) bool {
+	g.mu.Lock()
+	defer g.mu.Unlock()
+	c, ok := g.m[key]
+	if !ok {
+		return true
+	}
+	if c.dups == 0 {
+		delete(g.m, key)
+		return true
+	}
+	return false
+}
diff --git a/contrib/go/_std_1.20/src/internal/singleflight/ya.make b/contrib/go/_std_1.20/src/internal/singleflight/ya.make
new file mode 100644
index 0000000000..b44ecbcd79
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/singleflight/ya.make
@@ -0,0 +1,7 @@
+GO_LIBRARY()
+
+SRCS(
+    singleflight.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/syscall/execenv/execenv_default.go b/contrib/go/_std_1.20/src/internal/syscall/execenv/execenv_default.go
new file mode 100644
index 0000000000..335647c638
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/execenv/execenv_default.go
@@ -0,0 +1,19 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !windows
+
+package execenv
+
+import "syscall"
+
+// Default will return the default environment
+// variables based on the process attributes
+// provided.
+//
+// Defaults to syscall.Environ() on all platforms
+// other than Windows.
+func Default(sys *syscall.SysProcAttr) ([]string, error) {
+	return syscall.Environ(), nil
+}
diff --git a/contrib/go/_std_1.20/src/internal/syscall/execenv/execenv_windows.go b/contrib/go/_std_1.20/src/internal/syscall/execenv/execenv_windows.go
new file mode 100644
index 0000000000..a8aa1a644e
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/execenv/execenv_windows.go
@@ -0,0 +1,54 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build windows
+
+package execenv
+
+import (
+	"internal/syscall/windows"
+	"syscall"
+	"unicode/utf16"
+	"unsafe"
+)
+
+// Default will return the default environment
+// variables based on the process attributes
+// provided.
+//
+// If the process attributes contain a token, then
+// the environment variables will be sourced from
+// the defaults for that user token, otherwise they
+// will be sourced from syscall.Environ().
+func Default(sys *syscall.SysProcAttr) (env []string, err error) {
+	if sys == nil || sys.Token == 0 {
+		return syscall.Environ(), nil
+	}
+	var block *uint16
+	err = windows.CreateEnvironmentBlock(&block, sys.Token, false)
+	if err != nil {
+		return nil, err
+	}
+	defer windows.DestroyEnvironmentBlock(block)
+	blockp := uintptr(unsafe.Pointer(block))
+	for {
+
+		// find NUL terminator
+		end := unsafe.Pointer(blockp)
+		for *(*uint16)(end) != 0 {
+			end = unsafe.Pointer(uintptr(end) + 2)
+		}
+
+		n := (uintptr(end) - uintptr(unsafe.Pointer(blockp))) / 2
+		if n == 0 {
+			// environment block ends with empty string
+			break
+		}
+
+		entry := (*[(1 << 30) - 1]uint16)(unsafe.Pointer(blockp))[:n:n]
+		env = append(env, string(utf16.Decode(entry)))
+		blockp += 2 * (uintptr(len(entry)) + 1)
+	}
+	return
+}
diff --git a/contrib/go/_std_1.20/src/internal/syscall/execenv/ya.make b/contrib/go/_std_1.20/src/internal/syscall/execenv/ya.make
new file mode 100644
index 0000000000..6e4227b8ca
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/execenv/ya.make
@@ -0,0 +1,21 @@
+GO_LIBRARY()
+
+IF (OS_DARWIN)
+    SRCS(
+        execenv_default.go
+    )
+ENDIF()
+
+IF (OS_LINUX)
+    SRCS(
+        execenv_default.go
+    )
+ENDIF()
+
+IF (OS_WINDOWS)
+    SRCS(
+        execenv_windows.go
+    )
+ENDIF()
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/syscall/unix/asm_darwin.s b/contrib/go/_std_1.20/src/internal/syscall/unix/asm_darwin.s
new file mode 100644
index 0000000000..8662c2846f
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/unix/asm_darwin.s
@@ -0,0 +1,24 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "textflag.h"
+
+TEXT ·libc_getentropy_trampoline(SB),NOSPLIT,$0-0; JMP libc_getentropy(SB)
+TEXT ·libc_getaddrinfo_trampoline(SB),NOSPLIT,$0-0; JMP libc_getaddrinfo(SB)
+TEXT ·libc_freeaddrinfo_trampoline(SB),NOSPLIT,$0-0; JMP libc_freeaddrinfo(SB)
+TEXT ·libc_getnameinfo_trampoline(SB),NOSPLIT,$0-0; JMP libc_getnameinfo(SB)
+TEXT ·libc_gai_strerror_trampoline(SB),NOSPLIT,$0-0; JMP libc_gai_strerror(SB)
+TEXT ·libresolv_res_9_ninit_trampoline(SB),NOSPLIT,$0-0; JMP libresolv_res_9_ninit(SB)
+TEXT ·libresolv_res_9_nclose_trampoline(SB),NOSPLIT,$0-0; JMP libresolv_res_9_nclose(SB)
+TEXT ·libresolv_res_9_nsearch_trampoline(SB),NOSPLIT,$0-0; JMP libresolv_res_9_nsearch(SB)
+TEXT ·libc_grantpt_trampoline(SB),NOSPLIT,$0-0; JMP libc_grantpt(SB)
+TEXT ·libc_unlockpt_trampoline(SB),NOSPLIT,$0-0; JMP libc_unlockpt(SB)
+TEXT ·libc_ptsname_r_trampoline(SB),NOSPLIT,$0-0; JMP libc_ptsname_r(SB)
+TEXT ·libc_posix_openpt_trampoline(SB),NOSPLIT,$0-0; JMP libc_posix_openpt(SB)
+TEXT ·libc_getgrouplist_trampoline(SB),NOSPLIT,$0-0; JMP libc_getgrouplist(SB)
+TEXT ·libc_getpwnam_r_trampoline(SB),NOSPLIT,$0-0; JMP libc_getpwnam_r(SB)
+TEXT ·libc_getpwuid_r_trampoline(SB),NOSPLIT,$0-0; JMP libc_getpwuid_r(SB)
+TEXT ·libc_getgrnam_r_trampoline(SB),NOSPLIT,$0-0; JMP libc_getgrnam_r(SB)
+TEXT ·libc_getgrgid_r_trampoline(SB),NOSPLIT,$0-0; JMP libc_getgrgid_r(SB)
+TEXT ·libc_sysconf_trampoline(SB),NOSPLIT,$0-0; JMP libc_sysconf(SB)
diff --git a/contrib/go/_std_1.20/src/internal/syscall/unix/at.go b/contrib/go/_std_1.20/src/internal/syscall/unix/at.go
new file mode 100644
index 0000000000..cfb6e410b1
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/unix/at.go
@@ -0,0 +1,40 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build dragonfly || freebsd || linux || netbsd || (openbsd && mips64)
+
+package unix
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+func Unlinkat(dirfd int, path string, flags int) error {
+	p, err := syscall.BytePtrFromString(path)
+	if err != nil {
+		return err
+	}
+
+	_, _, errno := syscall.Syscall(unlinkatTrap, uintptr(dirfd), uintptr(unsafe.Pointer(p)), uintptr(flags))
+	if errno != 0 {
+		return errno
+	}
+
+	return nil
+}
+
+func Openat(dirfd int, path string, flags int, perm uint32) (int, error) {
+	p, err := syscall.BytePtrFromString(path)
+	if err != nil {
+		return 0, err
+	}
+
+	fd, _, errno := syscall.Syscall6(openatTrap, uintptr(dirfd), uintptr(unsafe.Pointer(p)), uintptr(flags), uintptr(perm), 0, 0)
+	if errno != 0 {
+		return 0, errno
+	}
+
+	return int(fd), nil
+}
diff --git a/contrib/go/_std_1.20/src/internal/syscall/unix/at_fstatat.go b/contrib/go/_std_1.20/src/internal/syscall/unix/at_fstatat.go
new file mode 100644
index 0000000000..8f25fe9f64
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/unix/at_fstatat.go
@@ -0,0 +1,28 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build dragonfly || (linux && !loong64) || netbsd || (openbsd && mips64)
+
+package unix
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+func Fstatat(dirfd int, path string, stat *syscall.Stat_t, flags int) error {
+	var p *byte
+	p, err := syscall.BytePtrFromString(path)
+	if err != nil {
+		return err
+	}
+
+	_, _, errno := syscall.Syscall6(fstatatTrap, uintptr(dirfd), uintptr(unsafe.Pointer(p)), uintptr(unsafe.Pointer(stat)), uintptr(flags), 0, 0)
+	if errno != 0 {
+		return errno
+	}
+
+	return nil
+
+}
diff --git a/contrib/go/_std_1.20/src/internal/syscall/unix/at_libc2.go b/contrib/go/_std_1.20/src/internal/syscall/unix/at_libc2.go
new file mode 100644
index 0000000000..4eeb7717ed
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/unix/at_libc2.go
@@ -0,0 +1,34 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build darwin || (openbsd && !mips64)
+
+package unix
+
+import (
+	"syscall"
+	_ "unsafe" // for linkname
+
+)
+
+func Unlinkat(dirfd int, path string, flags int) error {
+	return unlinkat(dirfd, path, flags)
+}
+
+func Openat(dirfd int, path string, flags int, perm uint32) (int, error) {
+	return openat(dirfd, path, flags, perm)
+}
+
+func Fstatat(dirfd int, path string, stat *syscall.Stat_t, flags int) error {
+	return fstatat(dirfd, path, stat, flags)
+}
+
+//go:linkname unlinkat syscall.unlinkat
+func unlinkat(dirfd int, path string, flags int) error
+
+//go:linkname openat syscall.openat
+func openat(dirfd int, path string, flags int, perm uint32) (int, error)
+
+//go:linkname fstatat syscall.fstatat
+func fstatat(dirfd int, path string, stat *syscall.Stat_t, flags int) error
diff --git a/contrib/go/_std_1.20/src/internal/syscall/unix/at_sysnum_darwin.go b/contrib/go/_std_1.20/src/internal/syscall/unix/at_sysnum_darwin.go
new file mode 100644
index 0000000000..aaaaa4751c
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/unix/at_sysnum_darwin.go
@@ -0,0 +1,8 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package unix
+
+const AT_REMOVEDIR = 0x80
+const AT_SYMLINK_NOFOLLOW = 0x0020
diff --git a/contrib/go/_std_1.20/src/internal/syscall/unix/at_sysnum_fstatat_linux.go b/contrib/go/_std_1.20/src/internal/syscall/unix/at_sysnum_fstatat_linux.go
new file mode 100644
index 0000000000..73a3da5bff
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/unix/at_sysnum_fstatat_linux.go
@@ -0,0 +1,11 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build arm64 || riscv64
+
+package unix
+
+import "syscall"
+
+const fstatatTrap uintptr = syscall.SYS_FSTATAT
diff --git a/contrib/go/_std_1.20/src/internal/syscall/unix/at_sysnum_linux.go b/contrib/go/_std_1.20/src/internal/syscall/unix/at_sysnum_linux.go
new file mode 100644
index 0000000000..b9b8495e32
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/unix/at_sysnum_linux.go
@@ -0,0 +1,17 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package unix
+
+import "syscall"
+
+const unlinkatTrap uintptr = syscall.SYS_UNLINKAT
+const openatTrap uintptr = syscall.SYS_OPENAT
+
+const (
+	AT_EACCESS          = 0x200
+	AT_FDCWD            = -0x64
+	AT_REMOVEDIR        = 0x200
+	AT_SYMLINK_NOFOLLOW = 0x100
+)
diff --git a/contrib/go/_std_1.20/src/internal/syscall/unix/at_sysnum_newfstatat_linux.go b/contrib/go/_std_1.20/src/internal/syscall/unix/at_sysnum_newfstatat_linux.go
new file mode 100644
index 0000000000..76edf67522
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/unix/at_sysnum_newfstatat_linux.go
@@ -0,0 +1,11 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build amd64 || mips64 || mips64le || ppc64 || ppc64le || s390x
+
+package unix
+
+import "syscall"
+
+const fstatatTrap uintptr = syscall.SYS_NEWFSTATAT
diff --git a/contrib/go/_std_1.20/src/internal/syscall/unix/constants.go b/contrib/go/_std_1.20/src/internal/syscall/unix/constants.go
new file mode 100644
index 0000000000..e324589705
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/unix/constants.go
@@ -0,0 +1,13 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build unix
+
+package unix
+
+const (
+	R_OK = 0x4
+	W_OK = 0x2
+	X_OK = 0x1
+)
diff --git a/contrib/go/_std_1.20/src/internal/syscall/unix/copy_file_range_linux.go b/contrib/go/_std_1.20/src/internal/syscall/unix/copy_file_range_linux.go
new file mode 100644
index 0000000000..cf0a279a7a
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/unix/copy_file_range_linux.go
@@ -0,0 +1,26 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package unix
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+func CopyFileRange(rfd int, roff *int64, wfd int, woff *int64, len int, flags int) (n int, err error) {
+	r1, _, errno := syscall.Syscall6(copyFileRangeTrap,
+		uintptr(rfd),
+		uintptr(unsafe.Pointer(roff)),
+		uintptr(wfd),
+		uintptr(unsafe.Pointer(woff)),
+		uintptr(len),
+		uintptr(flags),
+	)
+	n = int(r1)
+	if errno != 0 {
+		err = errno
+	}
+	return
+}
diff --git a/contrib/go/_std_1.20/src/internal/syscall/unix/eaccess_linux.go b/contrib/go/_std_1.20/src/internal/syscall/unix/eaccess_linux.go
new file mode 100644
index 0000000000..5695a5e4ce
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/unix/eaccess_linux.go
@@ -0,0 +1,11 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package unix
+
+import "syscall"
+
+func Eaccess(path string, mode uint32) error {
+	return syscall.Faccessat(AT_FDCWD, path, mode, AT_EACCESS)
+}
diff --git a/contrib/go/_std_1.20/src/internal/syscall/unix/eaccess_other.go b/contrib/go/_std_1.20/src/internal/syscall/unix/eaccess_other.go
new file mode 100644
index 0000000000..23be118297
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/unix/eaccess_other.go
@@ -0,0 +1,13 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build unix && !linux
+
+package unix
+
+import "syscall"
+
+func Eaccess(path string, mode uint32) error {
+	return syscall.ENOSYS
+}
diff --git a/contrib/go/_std_1.20/src/internal/syscall/unix/getentropy_darwin.go b/contrib/go/_std_1.20/src/internal/syscall/unix/getentropy_darwin.go
new file mode 100644
index 0000000000..834099ffed
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/unix/getentropy_darwin.go
@@ -0,0 +1,28 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build darwin && !ios
+
+package unix
+
+import (
+	"internal/abi"
+	"unsafe"
+)
+
+//go:cgo_import_dynamic libc_getentropy getentropy "/usr/lib/libSystem.B.dylib"
+
+func libc_getentropy_trampoline()
+
+// GetEntropy calls the macOS getentropy system call.
+func GetEntropy(p []byte) error {
+	_, _, errno := syscall_syscall(abi.FuncPCABI0(libc_getentropy_trampoline),
+		uintptr(unsafe.Pointer(&p[0])),
+		uintptr(len(p)),
+		0)
+	if errno != 0 {
+		return errno
+	}
+	return nil
+}
diff --git a/contrib/go/_std_1.20/src/internal/syscall/unix/getrandom.go b/contrib/go/_std_1.20/src/internal/syscall/unix/getrandom.go
new file mode 100644
index 0000000000..a6659331e4
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/unix/getrandom.go
@@ -0,0 +1,39 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build dragonfly || freebsd || linux
+
+package unix
+
+import (
+	"sync/atomic"
+	"syscall"
+	"unsafe"
+)
+
+var getrandomUnsupported int32 // atomic
+
+// GetRandomFlag is a flag supported by the getrandom system call.
+type GetRandomFlag uintptr
+
+// GetRandom calls the getrandom system call.
+func GetRandom(p []byte, flags GetRandomFlag) (n int, err error) {
+	if len(p) == 0 {
+		return 0, nil
+	}
+	if atomic.LoadInt32(&getrandomUnsupported) != 0 {
+		return 0, syscall.ENOSYS
+	}
+	r1, _, errno := syscall.Syscall(getrandomTrap,
+		uintptr(unsafe.Pointer(&p[0])),
+		uintptr(len(p)),
+		uintptr(flags))
+	if errno != 0 {
+		if errno == syscall.ENOSYS {
+			atomic.StoreInt32(&getrandomUnsupported, 1)
+		}
+		return 0, errno
+	}
+	return int(r1), nil
+}
diff --git a/contrib/go/_std_1.20/src/internal/syscall/unix/getrandom_linux.go b/contrib/go/_std_1.20/src/internal/syscall/unix/getrandom_linux.go
new file mode 100644
index 0000000000..8ccd8d328a
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/unix/getrandom_linux.go
@@ -0,0 +1,13 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package unix
+
+const (
+	// GRND_NONBLOCK means return EAGAIN rather than blocking.
+	GRND_NONBLOCK GetRandomFlag = 0x0001
+
+	// GRND_RANDOM means use the /dev/random pool instead of /dev/urandom.
+	GRND_RANDOM GetRandomFlag = 0x0002
+)
diff --git a/contrib/go/_std_1.20/src/internal/syscall/unix/kernel_version_linux.go b/contrib/go/_std_1.20/src/internal/syscall/unix/kernel_version_linux.go
new file mode 100644
index 0000000000..71e8aa4c57
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/unix/kernel_version_linux.go
@@ -0,0 +1,42 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package unix
+
+import (
+	"syscall"
+)
+
+// KernelVersion returns major and minor kernel version numbers, parsed from
+// the syscall.Uname's Release field, or 0, 0 if the version can't be obtained
+// or parsed.
+//
+// Currently only implemented for Linux.
+func KernelVersion() (major, minor int) {
+	var uname syscall.Utsname
+	if err := syscall.Uname(&uname); err != nil {
+		return
+	}
+
+	var (
+		values    [2]int
+		value, vi int
+	)
+	for _, c := range uname.Release {
+		if '0' <= c && c <= '9' {
+			value = (value * 10) + int(c-'0')
+		} else {
+			// Note that we're assuming N.N.N here.
+			// If we see anything else, we are likely to mis-parse it.
+			values[vi] = value
+			vi++
+			if vi >= len(values) {
+				break
+			}
+			value = 0
+		}
+	}
+
+	return values[0], values[1]
+}
diff --git a/contrib/go/_std_1.20/src/internal/syscall/unix/kernel_version_other.go b/contrib/go/_std_1.20/src/internal/syscall/unix/kernel_version_other.go
new file mode 100644
index 0000000000..00af9f2ba0
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/unix/kernel_version_other.go
@@ -0,0 +1,11 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !linux
+
+package unix
+
+func KernelVersion() (major int, minor int) {
+	return 0, 0
+}
diff --git a/contrib/go/_std_1.20/src/internal/syscall/unix/net.go b/contrib/go/_std_1.20/src/internal/syscall/unix/net.go
new file mode 100644
index 0000000000..5618d40ae0
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/unix/net.go
@@ -0,0 +1,44 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build unix
+
+package unix
+
+import (
+	"syscall"
+	_ "unsafe"
+)
+
+//go:linkname RecvfromInet4 syscall.recvfromInet4
+//go:noescape
+func RecvfromInet4(fd int, p []byte, flags int, from *syscall.SockaddrInet4) (int, error)
+
+//go:linkname RecvfromInet6 syscall.recvfromInet6
+//go:noescape
+func RecvfromInet6(fd int, p []byte, flags int, from *syscall.SockaddrInet6) (n int, err error)
+
+//go:linkname SendtoInet4 syscall.sendtoInet4
+//go:noescape
+func SendtoInet4(fd int, p []byte, flags int, to *syscall.SockaddrInet4) (err error)
+
+//go:linkname SendtoInet6 syscall.sendtoInet6
+//go:noescape
+func SendtoInet6(fd int, p []byte, flags int, to *syscall.SockaddrInet6) (err error)
+
+//go:linkname SendmsgNInet4 syscall.sendmsgNInet4
+//go:noescape
+func SendmsgNInet4(fd int, p, oob []byte, to *syscall.SockaddrInet4, flags int) (n int, err error)
+
+//go:linkname SendmsgNInet6 syscall.sendmsgNInet6
+//go:noescape
+func SendmsgNInet6(fd int, p, oob []byte, to *syscall.SockaddrInet6, flags int) (n int, err error)
+
+//go:linkname RecvmsgInet4 syscall.recvmsgInet4
+//go:noescape
+func RecvmsgInet4(fd int, p, oob []byte, flags int, from *syscall.SockaddrInet4) (n, oobn int, recvflags int, err error)
+
+//go:linkname RecvmsgInet6 syscall.recvmsgInet6
+//go:noescape
+func RecvmsgInet6(fd int, p, oob []byte, flags int, from *syscall.SockaddrInet6) (n, oobn int, recvflags int, err error)
diff --git a/contrib/go/_std_1.20/src/internal/syscall/unix/net_darwin.go b/contrib/go/_std_1.20/src/internal/syscall/unix/net_darwin.go
new file mode 100644
index 0000000000..b9da4f1dc7
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/unix/net_darwin.go
@@ -0,0 +1,161 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package unix
+
+import (
+	"internal/abi"
+	"syscall"
+	"unsafe"
+)
+
+const (
+	AI_CANONNAME = 0x2
+	AI_ALL       = 0x100
+	AI_V4MAPPED  = 0x800
+	AI_MASK      = 0x1407
+
+	EAI_AGAIN    = 2
+	EAI_NONAME   = 8
+	EAI_SYSTEM   = 11
+	EAI_OVERFLOW = 14
+
+	NI_NAMEREQD = 4
+)
+
+type Addrinfo struct {
+	Flags     int32
+	Family    int32
+	Socktype  int32
+	Protocol  int32
+	Addrlen   uint32
+	Canonname *byte
+	Addr      *syscall.RawSockaddr
+	Next      *Addrinfo
+}
+
+//go:cgo_ldflag "-lresolv"
+
+//go:cgo_import_dynamic libc_getaddrinfo getaddrinfo "/usr/lib/libSystem.B.dylib"
+func libc_getaddrinfo_trampoline()
+
+func Getaddrinfo(hostname, servname *byte, hints *Addrinfo, res **Addrinfo) (int, error) {
+	gerrno, _, errno := syscall_syscall6(abi.FuncPCABI0(libc_getaddrinfo_trampoline),
+		uintptr(unsafe.Pointer(hostname)),
+		uintptr(unsafe.Pointer(servname)),
+		uintptr(unsafe.Pointer(hints)),
+		uintptr(unsafe.Pointer(res)),
+		0,
+		0)
+	var err error
+	if errno != 0 {
+		err = errno
+	}
+	return int(gerrno), err
+}
+
+//go:cgo_import_dynamic libc_freeaddrinfo freeaddrinfo "/usr/lib/libSystem.B.dylib"
+func libc_freeaddrinfo_trampoline()
+
+func Freeaddrinfo(ai *Addrinfo) {
+	syscall_syscall6(abi.FuncPCABI0(libc_freeaddrinfo_trampoline),
+		uintptr(unsafe.Pointer(ai)),
+		0, 0, 0, 0, 0)
+}
+
+//go:cgo_import_dynamic libc_getnameinfo getnameinfo "/usr/lib/libSystem.B.dylib"
+func libc_getnameinfo_trampoline()
+
+func Getnameinfo(sa *syscall.RawSockaddr, salen int, host *byte, hostlen int, serv *byte, servlen int, flags int) (int, error) {
+	gerrno, _, errno := syscall_syscall9(abi.FuncPCABI0(libc_getnameinfo_trampoline),
+		uintptr(unsafe.Pointer(sa)),
+		uintptr(salen),
+		uintptr(unsafe.Pointer(host)),
+		uintptr(hostlen),
+		uintptr(unsafe.Pointer(serv)),
+		uintptr(servlen),
+		uintptr(flags),
+		0,
+		0)
+	var err error
+	if errno != 0 {
+		err = errno
+	}
+	return int(gerrno), err
+}
+
+//go:cgo_import_dynamic libc_gai_strerror gai_strerror "/usr/lib/libSystem.B.dylib"
+func libc_gai_strerror_trampoline()
+
+func GaiStrerror(ecode int) string {
+	r1, _, _ := syscall_syscall(abi.FuncPCABI0(libc_gai_strerror_trampoline),
+		uintptr(ecode),
+		0, 0)
+	return GoString((*byte)(unsafe.Pointer(r1)))
+}
+
+// Implemented in the runtime package.
+func gostring(*byte) string
+
+func GoString(p *byte) string {
+	return gostring(p)
+}
+
+//go:linkname syscall_syscall syscall.syscall
+func syscall_syscall(fn, a1, a2, a3 uintptr) (r1, r2 uintptr, err syscall.Errno)
+
+//go:linkname syscall_syscallPtr syscall.syscallPtr
+func syscall_syscallPtr(fn, a1, a2, a3 uintptr) (r1, r2 uintptr, err syscall.Errno)
+
+//go:linkname syscall_syscall6 syscall.syscall6
+func syscall_syscall6(fn, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err syscall.Errno)
+
+//go:linkname syscall_syscall6X syscall.syscall6X
+func syscall_syscall6X(fn, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err syscall.Errno)
+
+//go:linkname syscall_syscall9 syscall.syscall9
+func syscall_syscall9(fn, a1, a2, a3, a4, a5, a6, a7, a8, a9 uintptr) (r1, r2 uintptr, err syscall.Errno)
+
+type ResState struct {
+	unexported [70]uintptr
+}
+
+//go:cgo_import_dynamic libresolv_res_9_ninit res_9_ninit "/usr/lib/libresolv.9.dylib"
+func libresolv_res_9_ninit_trampoline()
+
+func ResNinit(state *ResState) error {
+	_, _, errno := syscall_syscall(abi.FuncPCABI0(libresolv_res_9_ninit_trampoline),
+		uintptr(unsafe.Pointer(state)),
+		0, 0)
+	if errno != 0 {
+		return errno
+	}
+	return nil
+}
+
+//go:cgo_import_dynamic libresolv_res_9_nclose res_9_nclose "/usr/lib/libresolv.9.dylib"
+func libresolv_res_9_nclose_trampoline()
+
+func ResNclose(state *ResState) {
+	syscall_syscall(abi.FuncPCABI0(libresolv_res_9_nclose_trampoline),
+		uintptr(unsafe.Pointer(state)),
+		0, 0)
+}
+
+//go:cgo_import_dynamic libresolv_res_9_nsearch res_9_nsearch "/usr/lib/libresolv.9.dylib"
+func libresolv_res_9_nsearch_trampoline()
+
+func ResNsearch(state *ResState, dname *byte, class, typ int, ans *byte, anslen int) (int, error) {
+	r1, _, errno := syscall_syscall6(abi.FuncPCABI0(libresolv_res_9_nsearch_trampoline),
+		uintptr(unsafe.Pointer(state)),
+		uintptr(unsafe.Pointer(dname)),
+		uintptr(class),
+		uintptr(typ),
+		uintptr(unsafe.Pointer(ans)),
+		uintptr(anslen))
+	if errno != 0 {
+		return 0, errno
+	}
+	return int(int32(r1)), nil
+}
diff --git a/contrib/go/_std_1.20/src/internal/syscall/unix/nonblocking.go b/contrib/go/_std_1.20/src/internal/syscall/unix/nonblocking.go
new file mode 100644
index 0000000000..6c6f0674d6
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/unix/nonblocking.go
@@ -0,0 +1,25 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build dragonfly || freebsd || linux || netbsd || (openbsd && mips64)
+
+package unix
+
+import "syscall"
+
+// FcntlSyscall is the number for the fcntl system call. This is
+// usually SYS_FCNTL, but can be overridden to SYS_FCNTL64.
+var FcntlSyscall uintptr = syscall.SYS_FCNTL
+
+func IsNonblock(fd int) (nonblocking bool, err error) {
+	flag, _, e1 := syscall.Syscall(FcntlSyscall, uintptr(fd), uintptr(syscall.F_GETFL), 0)
+	if e1 != 0 {
+		return false, e1
+	}
+	return flag&syscall.O_NONBLOCK != 0, nil
+}
+
+func HasNonblockFlag(flag int) bool {
+	return flag&syscall.O_NONBLOCK != 0
+}
diff --git a/contrib/go/_std_1.20/src/internal/syscall/unix/nonblocking_libc.go b/contrib/go/_std_1.20/src/internal/syscall/unix/nonblocking_libc.go
new file mode 100644
index 0000000000..56cac5b5cd
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/unix/nonblocking_libc.go
@@ -0,0 +1,30 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build aix || darwin || (openbsd && !mips64) || solaris
+
+package unix
+
+import (
+	"syscall"
+	_ "unsafe" // for go:linkname
+
+)
+
+func IsNonblock(fd int) (nonblocking bool, err error) {
+	flag, e1 := fcntl(fd, syscall.F_GETFL, 0)
+	if e1 != nil {
+		return false, e1
+	}
+	return flag&syscall.O_NONBLOCK != 0, nil
+}
+
+func HasNonblockFlag(flag int) bool {
+	return flag&syscall.O_NONBLOCK != 0
+}
+
+// Implemented in the syscall package.
+//
+//go:linkname fcntl syscall.fcntl
+func fcntl(fd int, cmd int, arg int) (int, error)
diff --git a/contrib/go/_std_1.20/src/internal/syscall/unix/pty_darwin.go b/contrib/go/_std_1.20/src/internal/syscall/unix/pty_darwin.go
new file mode 100644
index 0000000000..b43321a42e
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/unix/pty_darwin.go
@@ -0,0 +1,65 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package unix
+
+import (
+	"internal/abi"
+	"unsafe"
+)
+
+//go:cgo_import_dynamic libc_grantpt grantpt "/usr/lib/libSystem.B.dylib"
+func libc_grantpt_trampoline()
+
+func Grantpt(fd int) error {
+	_, _, errno := syscall_syscall6(abi.FuncPCABI0(libc_grantpt_trampoline), uintptr(fd), 0, 0, 0, 0, 0)
+	if errno != 0 {
+		return errno
+	}
+	return nil
+}
+
+//go:cgo_import_dynamic libc_unlockpt unlockpt "/usr/lib/libSystem.B.dylib"
+func libc_unlockpt_trampoline()
+
+func Unlockpt(fd int) error {
+	_, _, errno := syscall_syscall6(abi.FuncPCABI0(libc_unlockpt_trampoline), uintptr(fd), 0, 0, 0, 0, 0)
+	if errno != 0 {
+		return errno
+	}
+	return nil
+}
+
+//go:cgo_import_dynamic libc_ptsname_r ptsname_r "/usr/lib/libSystem.B.dylib"
+func libc_ptsname_r_trampoline()
+
+func Ptsname(fd int) (string, error) {
+	buf := make([]byte, 256)
+	_, _, errno := syscall_syscall6(abi.FuncPCABI0(libc_ptsname_r_trampoline),
+		uintptr(fd),
+		uintptr(unsafe.Pointer(&buf[0])),
+		uintptr(len(buf)-1),
+		0, 0, 0)
+	if errno != 0 {
+		return "", errno
+	}
+	for i, c := range buf {
+		if c == 0 {
+			buf = buf[:i]
+			break
+		}
+	}
+	return string(buf), nil
+}
+
+//go:cgo_import_dynamic libc_posix_openpt posix_openpt "/usr/lib/libSystem.B.dylib"
+func libc_posix_openpt_trampoline()
+
+func PosixOpenpt(flag int) (fd int, err error) {
+	ufd, _, errno := syscall_syscall6(abi.FuncPCABI0(libc_posix_openpt_trampoline), uintptr(flag), 0, 0, 0, 0, 0)
+	if errno != 0 {
+		return -1, errno
+	}
+	return int(ufd), nil
+}
diff --git a/contrib/go/_std_1.20/src/internal/syscall/unix/sysnum_linux_amd64.go b/contrib/go/_std_1.20/src/internal/syscall/unix/sysnum_linux_amd64.go
new file mode 100644
index 0000000000..ae5239ebfb
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/unix/sysnum_linux_amd64.go
@@ -0,0 +1,10 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package unix
+
+const (
+	getrandomTrap     uintptr = 318
+	copyFileRangeTrap uintptr = 326
+)
diff --git a/contrib/go/_std_1.20/src/internal/syscall/unix/sysnum_linux_generic.go b/contrib/go/_std_1.20/src/internal/syscall/unix/sysnum_linux_generic.go
new file mode 100644
index 0000000000..8c132c6bf5
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/unix/sysnum_linux_generic.go
@@ -0,0 +1,16 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build linux && (arm64 || loong64 || riscv64)
+
+package unix
+
+// This file is named "generic" because at a certain point Linux started
+// standardizing on system call numbers across architectures. So far this
+// means only arm64 loong64 and riscv64 use the standard numbers.
+
+const (
+	getrandomTrap     uintptr = 278
+	copyFileRangeTrap uintptr = 285
+)
diff --git a/contrib/go/_std_1.20/src/internal/syscall/unix/user_darwin.go b/contrib/go/_std_1.20/src/internal/syscall/unix/user_darwin.go
new file mode 100644
index 0000000000..d05acdaa49
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/unix/user_darwin.go
@@ -0,0 +1,121 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package unix
+
+import (
+	"internal/abi"
+	"syscall"
+	"unsafe"
+)
+
+//go:cgo_import_dynamic libc_getgrouplist getgrouplist "/usr/lib/libSystem.B.dylib"
+func libc_getgrouplist_trampoline()
+
+func Getgrouplist(name *byte, gid uint32, gids *uint32, n *int32) error {
+	_, _, errno := syscall_syscall6(abi.FuncPCABI0(libc_getgrouplist_trampoline),
+		uintptr(unsafe.Pointer(name)), uintptr(gid), uintptr(unsafe.Pointer(gids)),
+		uintptr(unsafe.Pointer(n)), 0, 0)
+	if errno != 0 {
+		return errno
+	}
+	return nil
+}
+
+const (
+	SC_GETGR_R_SIZE_MAX = 0x46
+	SC_GETPW_R_SIZE_MAX = 0x47
+)
+
+type Passwd struct {
+	Name   *byte
+	Passwd *byte
+	Uid    uint32 // uid_t
+	Gid    uint32 // gid_t
+	Change int64  // time_t
+	Class  *byte
+	Gecos  *byte
+	Dir    *byte
+	Shell  *byte
+	Expire int64 // time_t
+}
+
+type Group struct {
+	Name   *byte
+	Passwd *byte
+	Gid    uint32 // gid_t
+	Mem    **byte
+}
+
+//go:cgo_import_dynamic libc_getpwnam_r getpwnam_r  "/usr/lib/libSystem.B.dylib"
+func libc_getpwnam_r_trampoline()
+
+func Getpwnam(name *byte, pwd *Passwd, buf *byte, size uintptr, result **Passwd) syscall.Errno {
+	// Note: Returns an errno as its actual result, not in global errno.
+	errno, _, _ := syscall_syscall6(abi.FuncPCABI0(libc_getpwnam_r_trampoline),
+		uintptr(unsafe.Pointer(name)),
+		uintptr(unsafe.Pointer(pwd)),
+		uintptr(unsafe.Pointer(buf)),
+		size,
+		uintptr(unsafe.Pointer(result)),
+		0)
+	return syscall.Errno(errno)
+}
+
+//go:cgo_import_dynamic libc_getpwuid_r getpwuid_r  "/usr/lib/libSystem.B.dylib"
+func libc_getpwuid_r_trampoline()
+
+func Getpwuid(uid uint32, pwd *Passwd, buf *byte, size uintptr, result **Passwd) syscall.Errno {
+	// Note: Returns an errno as its actual result, not in global errno.
+	errno, _, _ := syscall_syscall6(abi.FuncPCABI0(libc_getpwuid_r_trampoline),
+		uintptr(uid),
+		uintptr(unsafe.Pointer(pwd)),
+		uintptr(unsafe.Pointer(buf)),
+		size,
+		uintptr(unsafe.Pointer(result)),
+		0)
+	return syscall.Errno(errno)
+}
+
+//go:cgo_import_dynamic libc_getgrnam_r getgrnam_r  "/usr/lib/libSystem.B.dylib"
+func libc_getgrnam_r_trampoline()
+
+func Getgrnam(name *byte, grp *Group, buf *byte, size uintptr, result **Group) syscall.Errno {
+	// Note: Returns an errno as its actual result, not in global errno.
+	errno, _, _ := syscall_syscall6(abi.FuncPCABI0(libc_getgrnam_r_trampoline),
+		uintptr(unsafe.Pointer(name)),
+		uintptr(unsafe.Pointer(grp)),
+		uintptr(unsafe.Pointer(buf)),
+		size,
+		uintptr(unsafe.Pointer(result)),
+		0)
+	return syscall.Errno(errno)
+}
+
+//go:cgo_import_dynamic libc_getgrgid_r getgrgid_r  "/usr/lib/libSystem.B.dylib"
+func libc_getgrgid_r_trampoline()
+
+func Getgrgid(gid uint32, grp *Group, buf *byte, size uintptr, result **Group) syscall.Errno {
+	// Note: Returns an errno as its actual result, not in global errno.
+	errno, _, _ := syscall_syscall6(abi.FuncPCABI0(libc_getgrgid_r_trampoline),
+		uintptr(gid),
+		uintptr(unsafe.Pointer(grp)),
+		uintptr(unsafe.Pointer(buf)),
+		size,
+		uintptr(unsafe.Pointer(result)),
+		0)
+	return syscall.Errno(errno)
+}
+
+//go:cgo_import_dynamic libc_sysconf sysconf "/usr/lib/libSystem.B.dylib"
+func libc_sysconf_trampoline()
+
+func Sysconf(key int32) int64 {
+	val, _, errno := syscall_syscall6X(abi.FuncPCABI0(libc_sysconf_trampoline),
+		uintptr(key), 0, 0, 0, 0, 0)
+	if errno != 0 {
+		return -1
+	}
+	return int64(val)
+}
diff --git a/contrib/go/_std_1.20/src/internal/syscall/unix/ya.make b/contrib/go/_std_1.20/src/internal/syscall/unix/ya.make
new file mode 100644
index 0000000000..d7d1a71aab
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/unix/ya.make
@@ -0,0 +1,62 @@
+GO_LIBRARY()
+
+BUILD_ONLY_IF(WARNING OS_DARWIN OR OS_LINUX)
+
+IF (OS_DARWIN)
+    CGO_LDFLAGS(
+        -lresolv
+    )
+
+    SRCS(
+        asm_darwin.s
+        at_libc2.go
+        at_sysnum_darwin.go
+        constants.go
+        eaccess_other.go
+        getentropy_darwin.go
+        kernel_version_other.go
+        net.go
+        net_darwin.go
+        nonblocking_libc.go
+        pty_darwin.go
+        user_darwin.go
+    )
+ENDIF()
+
+IF (OS_LINUX)
+    SRCS(
+        at.go
+        at_fstatat.go
+        at_sysnum_linux.go
+        constants.go
+        copy_file_range_linux.go
+        eaccess_linux.go
+        getrandom.go
+        getrandom_linux.go
+        kernel_version_linux.go
+        net.go
+        nonblocking.go
+    )
+
+    IF (ARCH_ARM64)
+        SRCS(
+            at_sysnum_fstatat_linux.go
+            sysnum_linux_generic.go
+        )
+    ENDIF()
+
+    IF (ARCH_X86_64)
+        SRCS(
+            at_sysnum_newfstatat_linux.go
+            sysnum_linux_amd64.go
+        )
+    ENDIF()
+ENDIF()
+
+IF (OS_WINDOWS)
+    SRCS(
+        kernel_version_other.go
+    )
+ENDIF()
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/syscall/windows/memory_windows.go b/contrib/go/_std_1.20/src/internal/syscall/windows/memory_windows.go
new file mode 100644
index 0000000000..8fb34cf349
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/windows/memory_windows.go
@@ -0,0 +1,24 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package windows
+
+type MemoryBasicInformation struct {
+	// A pointer to the base address of the region of pages.
+	BaseAddress uintptr
+	// A pointer to the base address of a range of pages allocated by the VirtualAlloc function.
+	// The page pointed to by the BaseAddress member is contained within this allocation range.
+	AllocationBase uintptr
+	// The memory protection option when the region was initially allocated
+	AllocationProtect uint32
+	PartitionId       uint16
+	// The size of the region beginning at the base address in which all pages have identical attributes, in bytes.
+	RegionSize uintptr
+	// The state of the pages in the region.
+	State uint32
+	// The access protection of the pages in the region.
+	Protect uint32
+	// The type of pages in the region.
+	Type uint32
+}
diff --git a/contrib/go/_std_1.20/src/internal/syscall/windows/net_windows.go b/contrib/go/_std_1.20/src/internal/syscall/windows/net_windows.go
new file mode 100644
index 0000000000..3d3df7161c
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/windows/net_windows.go
@@ -0,0 +1,18 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package windows
+
+import (
+	"syscall"
+	_ "unsafe"
+)
+
+//go:linkname WSASendtoInet4 syscall.wsaSendtoInet4
+//go:noescape
+func WSASendtoInet4(s syscall.Handle, bufs *syscall.WSABuf, bufcnt uint32, sent *uint32, flags uint32, to *syscall.SockaddrInet4, overlapped *syscall.Overlapped, croutine *byte) (err error)
+
+//go:linkname WSASendtoInet6 syscall.wsaSendtoInet6
+//go:noescape
+func WSASendtoInet6(s syscall.Handle, bufs *syscall.WSABuf, bufcnt uint32, sent *uint32, flags uint32, to *syscall.SockaddrInet6, overlapped *syscall.Overlapped, croutine *byte) (err error)
diff --git a/contrib/go/_std_1.20/src/internal/syscall/windows/psapi_windows.go b/contrib/go/_std_1.20/src/internal/syscall/windows/psapi_windows.go
new file mode 100644
index 0000000000..b138e658a9
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/windows/psapi_windows.go
@@ -0,0 +1,20 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package windows
+
+type PROCESS_MEMORY_COUNTERS struct {
+	CB                         uint32
+	PageFaultCount             uint32
+	PeakWorkingSetSize         uintptr
+	WorkingSetSize             uintptr
+	QuotaPeakPagedPoolUsage    uintptr
+	QuotaPagedPoolUsage        uintptr
+	QuotaPeakNonPagedPoolUsage uintptr
+	QuotaNonPagedPoolUsage     uintptr
+	PagefileUsage              uintptr
+	PeakPagefileUsage          uintptr
+}
+
+//sys	GetProcessMemoryInfo(handle syscall.Handle, memCounters *PROCESS_MEMORY_COUNTERS, cb uint32) (err error) = psapi.GetProcessMemoryInfo
diff --git a/contrib/go/_std_1.20/src/internal/syscall/windows/registry/key.go b/contrib/go/_std_1.20/src/internal/syscall/windows/registry/key.go
new file mode 100644
index 0000000000..ce6397f1e2
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/windows/registry/key.go
@@ -0,0 +1,168 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build windows
+
+// Package registry provides access to the Windows registry.
+//
+// Here is a simple example, opening a registry key and reading a string value from it.
+//
+//	k, err := registry.OpenKey(registry.LOCAL_MACHINE, `SOFTWARE\Microsoft\Windows NT\CurrentVersion`, registry.QUERY_VALUE)
+//	if err != nil {
+//		log.Fatal(err)
+//	}
+//	defer k.Close()
+//
+//	s, _, err := k.GetStringValue("SystemRoot")
+//	if err != nil {
+//		log.Fatal(err)
+//	}
+//	fmt.Printf("Windows system root is %q\n", s)
+//
+// NOTE: This package is a copy of golang.org/x/sys/windows/registry
+// with KeyInfo.ModTime removed to prevent dependency cycles.
+package registry
+
+import (
+	"runtime"
+	"syscall"
+)
+
+const (
+	// Registry key security and access rights.
+	// See https://msdn.microsoft.com/en-us/library/windows/desktop/ms724878.aspx
+	// for details.
+	ALL_ACCESS         = 0xf003f
+	CREATE_LINK        = 0x00020
+	CREATE_SUB_KEY     = 0x00004
+	ENUMERATE_SUB_KEYS = 0x00008
+	EXECUTE            = 0x20019
+	NOTIFY             = 0x00010
+	QUERY_VALUE        = 0x00001
+	READ               = 0x20019
+	SET_VALUE          = 0x00002
+	WOW64_32KEY        = 0x00200
+	WOW64_64KEY        = 0x00100
+	WRITE              = 0x20006
+)
+
+// Key is a handle to an open Windows registry key.
+// Keys can be obtained by calling OpenKey; there are
+// also some predefined root keys such as CURRENT_USER.
+// Keys can be used directly in the Windows API.
+type Key syscall.Handle
+
+const (
+	// Windows defines some predefined root keys that are always open.
+	// An application can use these keys as entry points to the registry.
+	// Normally these keys are used in OpenKey to open new keys,
+	// but they can also be used anywhere a Key is required.
+	CLASSES_ROOT   = Key(syscall.HKEY_CLASSES_ROOT)
+	CURRENT_USER   = Key(syscall.HKEY_CURRENT_USER)
+	LOCAL_MACHINE  = Key(syscall.HKEY_LOCAL_MACHINE)
+	USERS          = Key(syscall.HKEY_USERS)
+	CURRENT_CONFIG = Key(syscall.HKEY_CURRENT_CONFIG)
+)
+
+// Close closes open key k.
+func (k Key) Close() error {
+	return syscall.RegCloseKey(syscall.Handle(k))
+}
+
+// OpenKey opens a new key with path name relative to key k.
+// It accepts any open key, including CURRENT_USER and others,
+// and returns the new key and an error.
+// The access parameter specifies desired access rights to the
+// key to be opened.
+func OpenKey(k Key, path string, access uint32) (Key, error) {
+	p, err := syscall.UTF16PtrFromString(path)
+	if err != nil {
+		return 0, err
+	}
+	var subkey syscall.Handle
+	err = syscall.RegOpenKeyEx(syscall.Handle(k), p, 0, access, &subkey)
+	if err != nil {
+		return 0, err
+	}
+	return Key(subkey), nil
+}
+
+// ReadSubKeyNames returns the names of subkeys of key k.
+func (k Key) ReadSubKeyNames() ([]string, error) {
+	// RegEnumKeyEx must be called repeatedly and to completion.
+	// During this time, this goroutine cannot migrate away from
+	// its current thread. See #49320.
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	names := make([]string, 0)
+	// Registry key size limit is 255 bytes and described there:
+	// https://msdn.microsoft.com/library/windows/desktop/ms724872.aspx
+	buf := make([]uint16, 256) //plus extra room for terminating zero byte
+loopItems:
+	for i := uint32(0); ; i++ {
+		l := uint32(len(buf))
+		for {
+			err := syscall.RegEnumKeyEx(syscall.Handle(k), i, &buf[0], &l, nil, nil, nil, nil)
+			if err == nil {
+				break
+			}
+			if err == syscall.ERROR_MORE_DATA {
+				// Double buffer size and try again.
+				l = uint32(2 * len(buf))
+				buf = make([]uint16, l)
+				continue
+			}
+			if err == _ERROR_NO_MORE_ITEMS {
+				break loopItems
+			}
+			return names, err
+		}
+		names = append(names, syscall.UTF16ToString(buf[:l]))
+	}
+	return names, nil
+}
+
+// CreateKey creates a key named path under open key k.
+// CreateKey returns the new key and a boolean flag that reports
+// whether the key already existed.
+// The access parameter specifies the access rights for the key
+// to be created.
+func CreateKey(k Key, path string, access uint32) (newk Key, openedExisting bool, err error) {
+	var h syscall.Handle
+	var d uint32
+	err = regCreateKeyEx(syscall.Handle(k), syscall.StringToUTF16Ptr(path),
+		0, nil, _REG_OPTION_NON_VOLATILE, access, nil, &h, &d)
+	if err != nil {
+		return 0, false, err
+	}
+	return Key(h), d == _REG_OPENED_EXISTING_KEY, nil
+}
+
+// DeleteKey deletes the subkey path of key k and its values.
+func DeleteKey(k Key, path string) error {
+	return regDeleteKey(syscall.Handle(k), syscall.StringToUTF16Ptr(path))
+}
+
+// A KeyInfo describes the statistics of a key. It is returned by Stat.
+type KeyInfo struct {
+	SubKeyCount     uint32
+	MaxSubKeyLen    uint32 // size of the key's subkey with the longest name, in Unicode characters, not including the terminating zero byte
+	ValueCount      uint32
+	MaxValueNameLen uint32 // size of the key's longest value name, in Unicode characters, not including the terminating zero byte
+	MaxValueLen     uint32 // longest data component among the key's values, in bytes
+	lastWriteTime   syscall.Filetime
+}
+
+// Stat retrieves information about the open key k.
+func (k Key) Stat() (*KeyInfo, error) {
+	var ki KeyInfo
+	err := syscall.RegQueryInfoKey(syscall.Handle(k), nil, nil, nil,
+		&ki.SubKeyCount, &ki.MaxSubKeyLen, nil, &ki.ValueCount,
+		&ki.MaxValueNameLen, &ki.MaxValueLen, nil, &ki.lastWriteTime)
+	if err != nil {
+		return nil, err
+	}
+	return &ki, nil
+}
diff --git a/contrib/go/_std_1.20/src/internal/syscall/windows/registry/syscall.go b/contrib/go/_std_1.20/src/internal/syscall/windows/registry/syscall.go
new file mode 100644
index 0000000000..cb315adade
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/windows/registry/syscall.go
@@ -0,0 +1,31 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build windows
+
+package registry
+
+import "syscall"
+
+const (
+	_REG_OPTION_NON_VOLATILE = 0
+
+	_REG_CREATED_NEW_KEY     = 1
+	_REG_OPENED_EXISTING_KEY = 2
+
+	_ERROR_NO_MORE_ITEMS syscall.Errno = 259
+)
+
+func LoadRegLoadMUIString() error {
+	return procRegLoadMUIStringW.Find()
+}
+
+//sys	regCreateKeyEx(key syscall.Handle, subkey *uint16, reserved uint32, class *uint16, options uint32, desired uint32, sa *syscall.SecurityAttributes, result *syscall.Handle, disposition *uint32) (regerrno error) = advapi32.RegCreateKeyExW
+//sys	regDeleteKey(key syscall.Handle, subkey *uint16) (regerrno error) = advapi32.RegDeleteKeyW
+//sys	regSetValueEx(key syscall.Handle, valueName *uint16, reserved uint32, vtype uint32, buf *byte, bufsize uint32) (regerrno error) = advapi32.RegSetValueExW
+//sys	regEnumValue(key syscall.Handle, index uint32, name *uint16, nameLen *uint32, reserved *uint32, valtype *uint32, buf *byte, buflen *uint32) (regerrno error) = advapi32.RegEnumValueW
+//sys	regDeleteValue(key syscall.Handle, name *uint16) (regerrno error) = advapi32.RegDeleteValueW
+//sys   regLoadMUIString(key syscall.Handle, name *uint16, buf *uint16, buflen uint32, buflenCopied *uint32, flags uint32, dir *uint16) (regerrno error) = advapi32.RegLoadMUIStringW
+
+//sys	expandEnvironmentStrings(src *uint16, dst *uint16, size uint32) (n uint32, err error) = kernel32.ExpandEnvironmentStringsW
diff --git a/contrib/go/_std_1.20/src/internal/syscall/windows/registry/value.go b/contrib/go/_std_1.20/src/internal/syscall/windows/registry/value.go
new file mode 100644
index 0000000000..025574015f
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/windows/registry/value.go
@@ -0,0 +1,372 @@
+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build windows
+
+package registry
+
+import (
+	"errors"
+	"syscall"
+	"unicode/utf16"
+	"unsafe"
+)
+
+const (
+	// Registry value types.
+	NONE                       = 0
+	SZ                         = 1
+	EXPAND_SZ                  = 2
+	BINARY                     = 3
+	DWORD                      = 4
+	DWORD_BIG_ENDIAN           = 5
+	LINK                       = 6
+	MULTI_SZ                   = 7
+	RESOURCE_LIST              = 8
+	FULL_RESOURCE_DESCRIPTOR   = 9
+	RESOURCE_REQUIREMENTS_LIST = 10
+	QWORD                      = 11
+)
+
+var (
+	// ErrShortBuffer is returned when the buffer was too short for the operation.
+	ErrShortBuffer = syscall.ERROR_MORE_DATA
+
+	// ErrNotExist is returned when a registry key or value does not exist.
+	ErrNotExist = syscall.ERROR_FILE_NOT_FOUND
+
+	// ErrUnexpectedType is returned by Get*Value when the value's type was unexpected.
+	ErrUnexpectedType = errors.New("unexpected key value type")
+)
+
+// GetValue retrieves the type and data for the specified value associated
+// with an open key k. It fills up buffer buf and returns the retrieved
+// byte count n. If buf is too small to fit the stored value it returns
+// ErrShortBuffer error along with the required buffer size n.
+// If no buffer is provided, it returns true and actual buffer size n.
+// If no buffer is provided, GetValue returns the value's type only.
+// If the value does not exist, the error returned is ErrNotExist.
+//
+// GetValue is a low level function. If value's type is known, use the appropriate
+// Get*Value function instead.
+func (k Key) GetValue(name string, buf []byte) (n int, valtype uint32, err error) {
+	pname, err := syscall.UTF16PtrFromString(name)
+	if err != nil {
+		return 0, 0, err
+	}
+	var pbuf *byte
+	if len(buf) > 0 {
+		pbuf = (*byte)(unsafe.Pointer(&buf[0]))
+	}
+	l := uint32(len(buf))
+	err = syscall.RegQueryValueEx(syscall.Handle(k), pname, nil, &valtype, pbuf, &l)
+	if err != nil {
+		return int(l), valtype, err
+	}
+	return int(l), valtype, nil
+}
+
+func (k Key) getValue(name string, buf []byte) (date []byte, valtype uint32, err error) {
+	p, err := syscall.UTF16PtrFromString(name)
+	if err != nil {
+		return nil, 0, err
+	}
+	var t uint32
+	n := uint32(len(buf))
+	for {
+		err = syscall.RegQueryValueEx(syscall.Handle(k), p, nil, &t, (*byte)(unsafe.Pointer(&buf[0])), &n)
+		if err == nil {
+			return buf[:n], t, nil
+		}
+		if err != syscall.ERROR_MORE_DATA {
+			return nil, 0, err
+		}
+		if n <= uint32(len(buf)) {
+			return nil, 0, err
+		}
+		buf = make([]byte, n)
+	}
+}
+
+// GetStringValue retrieves the string value for the specified
+// value name associated with an open key k. It also returns the value's type.
+// If value does not exist, GetStringValue returns ErrNotExist.
+// If value is not SZ or EXPAND_SZ, it will return the correct value
+// type and ErrUnexpectedType.
+func (k Key) GetStringValue(name string) (val string, valtype uint32, err error) {
+	data, typ, err2 := k.getValue(name, make([]byte, 64))
+	if err2 != nil {
+		return "", typ, err2
+	}
+	switch typ {
+	case SZ, EXPAND_SZ:
+	default:
+		return "", typ, ErrUnexpectedType
+	}
+	if len(data) == 0 {
+		return "", typ, nil
+	}
+	u := (*[1 << 29]uint16)(unsafe.Pointer(&data[0]))[: len(data)/2 : len(data)/2]
+	return syscall.UTF16ToString(u), typ, nil
+}
+
+// GetMUIStringValue retrieves the localized string value for
+// the specified value name associated with an open key k.
+// If the value name doesn't exist or the localized string value
+// can't be resolved, GetMUIStringValue returns ErrNotExist.
+// GetMUIStringValue panics if the system doesn't support
+// regLoadMUIString; use LoadRegLoadMUIString to check if
+// regLoadMUIString is supported before calling this function.
+func (k Key) GetMUIStringValue(name string) (string, error) {
+	pname, err := syscall.UTF16PtrFromString(name)
+	if err != nil {
+		return "", err
+	}
+
+	buf := make([]uint16, 1024)
+	var buflen uint32
+	var pdir *uint16
+
+	err = regLoadMUIString(syscall.Handle(k), pname, &buf[0], uint32(len(buf)), &buflen, 0, pdir)
+	if err == syscall.ERROR_FILE_NOT_FOUND { // Try fallback path
+
+		// Try to resolve the string value using the system directory as
+		// a DLL search path; this assumes the string value is of the form
+		// @[path]\dllname,-strID but with no path given, e.g. @tzres.dll,-320.
+
+		// This approach works with tzres.dll but may have to be revised
+		// in the future to allow callers to provide custom search paths.
+
+		var s string
+		s, err = ExpandString("%SystemRoot%\\system32\\")
+		if err != nil {
+			return "", err
+		}
+		pdir, err = syscall.UTF16PtrFromString(s)
+		if err != nil {
+			return "", err
+		}
+
+		err = regLoadMUIString(syscall.Handle(k), pname, &buf[0], uint32(len(buf)), &buflen, 0, pdir)
+	}
+
+	for err == syscall.ERROR_MORE_DATA { // Grow buffer if needed
+		if buflen <= uint32(len(buf)) {
+			break // Buffer not growing, assume race; break
+		}
+		buf = make([]uint16, buflen)
+		err = regLoadMUIString(syscall.Handle(k), pname, &buf[0], uint32(len(buf)), &buflen, 0, pdir)
+	}
+
+	if err != nil {
+		return "", err
+	}
+
+	return syscall.UTF16ToString(buf), nil
+}
+
+// ExpandString expands environment-variable strings and replaces
+// them with the values defined for the current user.
+// Use ExpandString to expand EXPAND_SZ strings.
+func ExpandString(value string) (string, error) {
+	if value == "" {
+		return "", nil
+	}
+	p, err := syscall.UTF16PtrFromString(value)
+	if err != nil {
+		return "", err
+	}
+	r := make([]uint16, 100)
+	for {
+		n, err := expandEnvironmentStrings(p, &r[0], uint32(len(r)))
+		if err != nil {
+			return "", err
+		}
+		if n <= uint32(len(r)) {
+			return syscall.UTF16ToString(r[:n]), nil
+		}
+		r = make([]uint16, n)
+	}
+}
+
+// GetStringsValue retrieves the []string value for the specified
+// value name associated with an open key k. It also returns the value's type.
+// If value does not exist, GetStringsValue returns ErrNotExist.
+// If value is not MULTI_SZ, it will return the correct value
+// type and ErrUnexpectedType.
+func (k Key) GetStringsValue(name string) (val []string, valtype uint32, err error) {
+	data, typ, err2 := k.getValue(name, make([]byte, 64))
+	if err2 != nil {
+		return nil, typ, err2
+	}
+	if typ != MULTI_SZ {
+		return nil, typ, ErrUnexpectedType
+	}
+	if len(data) == 0 {
+		return nil, typ, nil
+	}
+	p := (*[1 << 29]uint16)(unsafe.Pointer(&data[0]))[: len(data)/2 : len(data)/2]
+	if len(p) == 0 {
+		return nil, typ, nil
+	}
+	if p[len(p)-1] == 0 {
+		p = p[:len(p)-1] // remove terminating null
+	}
+	val = make([]string, 0, 5)
+	from := 0
+	for i, c := range p {
+		if c == 0 {
+			val = append(val, string(utf16.Decode(p[from:i])))
+			from = i + 1
+		}
+	}
+	return val, typ, nil
+}
+
+// GetIntegerValue retrieves the integer value for the specified
+// value name associated with an open key k. It also returns the value's type.
+// If value does not exist, GetIntegerValue returns ErrNotExist.
+// If value is not DWORD or QWORD, it will return the correct value
+// type and ErrUnexpectedType.
+func (k Key) GetIntegerValue(name string) (val uint64, valtype uint32, err error) {
+	data, typ, err2 := k.getValue(name, make([]byte, 8))
+	if err2 != nil {
+		return 0, typ, err2
+	}
+	switch typ {
+	case DWORD:
+		if len(data) != 4 {
+			return 0, typ, errors.New("DWORD value is not 4 bytes long")
+		}
+		return uint64(*(*uint32)(unsafe.Pointer(&data[0]))), DWORD, nil
+	case QWORD:
+		if len(data) != 8 {
+			return 0, typ, errors.New("QWORD value is not 8 bytes long")
+		}
+		return uint64(*(*uint64)(unsafe.Pointer(&data[0]))), QWORD, nil
+	default:
+		return 0, typ, ErrUnexpectedType
+	}
+}
+
+// GetBinaryValue retrieves the binary value for the specified
+// value name associated with an open key k. It also returns the value's type.
+// If value does not exist, GetBinaryValue returns ErrNotExist.
+// If value is not BINARY, it will return the correct value
+// type and ErrUnexpectedType.
+func (k Key) GetBinaryValue(name string) (val []byte, valtype uint32, err error) {
+	data, typ, err2 := k.getValue(name, make([]byte, 64))
+	if err2 != nil {
+		return nil, typ, err2
+	}
+	if typ != BINARY {
+		return nil, typ, ErrUnexpectedType
+	}
+	return data, typ, nil
+}
+
+func (k Key) setValue(name string, valtype uint32, data []byte) error {
+	p, err := syscall.UTF16PtrFromString(name)
+	if err != nil {
+		return err
+	}
+	if len(data) == 0 {
+		return regSetValueEx(syscall.Handle(k), p, 0, valtype, nil, 0)
+	}
+	return regSetValueEx(syscall.Handle(k), p, 0, valtype, &data[0], uint32(len(data)))
+}
+
+// SetDWordValue sets the data and type of a name value
+// under key k to value and DWORD.
+func (k Key) SetDWordValue(name string, value uint32) error {
+	return k.setValue(name, DWORD, (*[4]byte)(unsafe.Pointer(&value))[:])
+}
+
+// SetQWordValue sets the data and type of a name value
+// under key k to value and QWORD.
+func (k Key) SetQWordValue(name string, value uint64) error {
+	return k.setValue(name, QWORD, (*[8]byte)(unsafe.Pointer(&value))[:])
+}
+
+func (k Key) setStringValue(name string, valtype uint32, value string) error {
+	v, err := syscall.UTF16FromString(value)
+	if err != nil {
+		return err
+	}
+	buf := (*[1 << 29]byte)(unsafe.Pointer(&v[0]))[: len(v)*2 : len(v)*2]
+	return k.setValue(name, valtype, buf)
+}
+
+// SetStringValue sets the data and type of a name value
+// under key k to value and SZ. The value must not contain a zero byte.
+func (k Key) SetStringValue(name, value string) error {
+	return k.setStringValue(name, SZ, value)
+}
+
+// SetExpandStringValue sets the data and type of a name value
+// under key k to value and EXPAND_SZ. The value must not contain a zero byte.
+func (k Key) SetExpandStringValue(name, value string) error {
+	return k.setStringValue(name, EXPAND_SZ, value)
+}
+
+// SetStringsValue sets the data and type of a name value
+// under key k to value and MULTI_SZ. The value strings
+// must not contain a zero byte.
+func (k Key) SetStringsValue(name string, value []string) error {
+	ss := ""
+	for _, s := range value {
+		for i := 0; i < len(s); i++ {
+			if s[i] == 0 {
+				return errors.New("string cannot have 0 inside")
+			}
+		}
+		ss += s + "\x00"
+	}
+	v := utf16.Encode([]rune(ss + "\x00"))
+	buf := (*[1 << 29]byte)(unsafe.Pointer(&v[0]))[: len(v)*2 : len(v)*2]
+	return k.setValue(name, MULTI_SZ, buf)
+}
+
+// SetBinaryValue sets the data and type of a name value
+// under key k to value and BINARY.
+func (k Key) SetBinaryValue(name string, value []byte) error {
+	return k.setValue(name, BINARY, value)
+}
+
+// DeleteValue removes a named value from the key k.
+func (k Key) DeleteValue(name string) error {
+	return regDeleteValue(syscall.Handle(k), syscall.StringToUTF16Ptr(name))
+}
+
+// ReadValueNames returns the value names of key k.
+func (k Key) ReadValueNames() ([]string, error) {
+	ki, err := k.Stat()
+	if err != nil {
+		return nil, err
+	}
+	names := make([]string, 0, ki.ValueCount)
+	buf := make([]uint16, ki.MaxValueNameLen+1) // extra room for terminating null character
+loopItems:
+	for i := uint32(0); ; i++ {
+		l := uint32(len(buf))
+		for {
+			err := regEnumValue(syscall.Handle(k), i, &buf[0], &l, nil, nil, nil, nil)
+			if err == nil {
+				break
+			}
+			if err == syscall.ERROR_MORE_DATA {
+				// Double buffer size and try again.
+				l = uint32(2 * len(buf))
+				buf = make([]uint16, l)
+				continue
+			}
+			if err == _ERROR_NO_MORE_ITEMS {
+				break loopItems
+			}
+			return names, err
+		}
+		names = append(names, syscall.UTF16ToString(buf[:l]))
+	}
+	return names, nil
+}
diff --git a/contrib/go/_std_1.20/src/internal/syscall/windows/registry/ya.make b/contrib/go/_std_1.20/src/internal/syscall/windows/registry/ya.make
new file mode 100644
index 0000000000..a883ca985a
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/windows/registry/ya.make
@@ -0,0 +1,14 @@
+GO_LIBRARY()
+
+BUILD_ONLY_IF(WARNING OS_WINDOWS)
+
+IF (OS_WINDOWS)
+    SRCS(
+        key.go
+        syscall.go
+        value.go
+        zsyscall_windows.go
+    )
+ENDIF()
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/syscall/windows/registry/zsyscall_windows.go b/contrib/go/_std_1.20/src/internal/syscall/windows/registry/zsyscall_windows.go
new file mode 100644
index 0000000000..cab1319374
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/windows/registry/zsyscall_windows.go
@@ -0,0 +1,107 @@
+// Code generated by 'go generate'; DO NOT EDIT.
+
+package registry
+
+import (
+	"internal/syscall/windows/sysdll"
+	"syscall"
+	"unsafe"
+)
+
+var _ unsafe.Pointer
+
+// Do the interface allocations only once for common
+// Errno values.
+const (
+	errnoERROR_IO_PENDING = 997
+)
+
+var (
+	errERROR_IO_PENDING error = syscall.Errno(errnoERROR_IO_PENDING)
+	errERROR_EINVAL     error = syscall.EINVAL
+)
+
+// errnoErr returns common boxed Errno values, to prevent
+// allocations at runtime.
+func errnoErr(e syscall.Errno) error {
+	switch e {
+	case 0:
+		return errERROR_EINVAL
+	case errnoERROR_IO_PENDING:
+		return errERROR_IO_PENDING
+	}
+	// TODO: add more here, after collecting data on the common
+	// error values see on Windows. (perhaps when running
+	// all.bat?)
+	return e
+}
+
+var (
+	modadvapi32 = syscall.NewLazyDLL(sysdll.Add("advapi32.dll"))
+	modkernel32 = syscall.NewLazyDLL(sysdll.Add("kernel32.dll"))
+
+	procRegCreateKeyExW           = modadvapi32.NewProc("RegCreateKeyExW")
+	procRegDeleteKeyW             = modadvapi32.NewProc("RegDeleteKeyW")
+	procRegDeleteValueW           = modadvapi32.NewProc("RegDeleteValueW")
+	procRegEnumValueW             = modadvapi32.NewProc("RegEnumValueW")
+	procRegLoadMUIStringW         = modadvapi32.NewProc("RegLoadMUIStringW")
+	procRegSetValueExW            = modadvapi32.NewProc("RegSetValueExW")
+	procExpandEnvironmentStringsW = modkernel32.NewProc("ExpandEnvironmentStringsW")
+)
+
+func regCreateKeyEx(key syscall.Handle, subkey *uint16, reserved uint32, class *uint16, options uint32, desired uint32, sa *syscall.SecurityAttributes, result *syscall.Handle, disposition *uint32) (regerrno error) {
+	r0, _, _ := syscall.Syscall9(procRegCreateKeyExW.Addr(), 9, uintptr(key), uintptr(unsafe.Pointer(subkey)), uintptr(reserved), uintptr(unsafe.Pointer(class)), uintptr(options), uintptr(desired), uintptr(unsafe.Pointer(sa)), uintptr(unsafe.Pointer(result)), uintptr(unsafe.Pointer(disposition)))
+	if r0 != 0 {
+		regerrno = syscall.Errno(r0)
+	}
+	return
+}
+
+func regDeleteKey(key syscall.Handle, subkey *uint16) (regerrno error) {
+	r0, _, _ := syscall.Syscall(procRegDeleteKeyW.Addr(), 2, uintptr(key), uintptr(unsafe.Pointer(subkey)), 0)
+	if r0 != 0 {
+		regerrno = syscall.Errno(r0)
+	}
+	return
+}
+
+func regDeleteValue(key syscall.Handle, name *uint16) (regerrno error) {
+	r0, _, _ := syscall.Syscall(procRegDeleteValueW.Addr(), 2, uintptr(key), uintptr(unsafe.Pointer(name)), 0)
+	if r0 != 0 {
+		regerrno = syscall.Errno(r0)
+	}
+	return
+}
+
+func regEnumValue(key syscall.Handle, index uint32, name *uint16, nameLen *uint32, reserved *uint32, valtype *uint32, buf *byte, buflen *uint32) (regerrno error) {
+	r0, _, _ := syscall.Syscall9(procRegEnumValueW.Addr(), 8, uintptr(key), uintptr(index), uintptr(unsafe.Pointer(name)), uintptr(unsafe.Pointer(nameLen)), uintptr(unsafe.Pointer(reserved)), uintptr(unsafe.Pointer(valtype)), uintptr(unsafe.Pointer(buf)), uintptr(unsafe.Pointer(buflen)), 0)
+	if r0 != 0 {
+		regerrno = syscall.Errno(r0)
+	}
+	return
+}
+
+func regLoadMUIString(key syscall.Handle, name *uint16, buf *uint16, buflen uint32, buflenCopied *uint32, flags uint32, dir *uint16) (regerrno error) {
+	r0, _, _ := syscall.Syscall9(procRegLoadMUIStringW.Addr(), 7, uintptr(key), uintptr(unsafe.Pointer(name)), uintptr(unsafe.Pointer(buf)), uintptr(buflen), uintptr(unsafe.Pointer(buflenCopied)), uintptr(flags), uintptr(unsafe.Pointer(dir)), 0, 0)
+	if r0 != 0 {
+		regerrno = syscall.Errno(r0)
+	}
+	return
+}
+
+func regSetValueEx(key syscall.Handle, valueName *uint16, reserved uint32, vtype uint32, buf *byte, bufsize uint32) (regerrno error) {
+	r0, _, _ := syscall.Syscall6(procRegSetValueExW.Addr(), 6, uintptr(key), uintptr(unsafe.Pointer(valueName)), uintptr(reserved), uintptr(vtype), uintptr(unsafe.Pointer(buf)), uintptr(bufsize))
+	if r0 != 0 {
+		regerrno = syscall.Errno(r0)
+	}
+	return
+}
+
+func expandEnvironmentStrings(src *uint16, dst *uint16, size uint32) (n uint32, err error) {
+	r0, _, e1 := syscall.Syscall(procExpandEnvironmentStringsW.Addr(), 3, uintptr(unsafe.Pointer(src)), uintptr(unsafe.Pointer(dst)), uintptr(size))
+	n = uint32(r0)
+	if n == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
diff --git a/contrib/go/_std_1.20/src/internal/syscall/windows/reparse_windows.go b/contrib/go/_std_1.20/src/internal/syscall/windows/reparse_windows.go
new file mode 100644
index 0000000000..6e111392f0
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/windows/reparse_windows.go
@@ -0,0 +1,90 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package windows
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+const (
+	FSCTL_SET_REPARSE_POINT    = 0x000900A4
+	IO_REPARSE_TAG_MOUNT_POINT = 0xA0000003
+
+	SYMLINK_FLAG_RELATIVE = 1
+)
+
+// These structures are described
+// in https://msdn.microsoft.com/en-us/library/cc232007.aspx
+// and https://msdn.microsoft.com/en-us/library/cc232006.aspx.
+
+type REPARSE_DATA_BUFFER struct {
+	ReparseTag        uint32
+	ReparseDataLength uint16
+	Reserved          uint16
+	DUMMYUNIONNAME    byte
+}
+
+// REPARSE_DATA_BUFFER_HEADER is a common part of REPARSE_DATA_BUFFER structure.
+type REPARSE_DATA_BUFFER_HEADER struct {
+	ReparseTag uint32
+	// The size, in bytes, of the reparse data that follows
+	// the common portion of the REPARSE_DATA_BUFFER element.
+	// This value is the length of the data starting at the
+	// SubstituteNameOffset field.
+	ReparseDataLength uint16
+	Reserved          uint16
+}
+
+type SymbolicLinkReparseBuffer struct {
+	// The integer that contains the offset, in bytes,
+	// of the substitute name string in the PathBuffer array,
+	// computed as an offset from byte 0 of PathBuffer. Note that
+	// this offset must be divided by 2 to get the array index.
+	SubstituteNameOffset uint16
+	// The integer that contains the length, in bytes, of the
+	// substitute name string. If this string is null-terminated,
+	// SubstituteNameLength does not include the Unicode null character.
+	SubstituteNameLength uint16
+	// PrintNameOffset is similar to SubstituteNameOffset.
+	PrintNameOffset uint16
+	// PrintNameLength is similar to SubstituteNameLength.
+	PrintNameLength uint16
+	// Flags specifies whether the substitute name is a full path name or
+	// a path name relative to the directory containing the symbolic link.
+	Flags      uint32
+	PathBuffer [1]uint16
+}
+
+// Path returns path stored in rb.
+func (rb *SymbolicLinkReparseBuffer) Path() string {
+	n1 := rb.SubstituteNameOffset / 2
+	n2 := (rb.SubstituteNameOffset + rb.SubstituteNameLength) / 2
+	return syscall.UTF16ToString((*[0xffff]uint16)(unsafe.Pointer(&rb.PathBuffer[0]))[n1:n2:n2])
+}
+
+type MountPointReparseBuffer struct {
+	// The integer that contains the offset, in bytes,
+	// of the substitute name string in the PathBuffer array,
+	// computed as an offset from byte 0 of PathBuffer. Note that
+	// this offset must be divided by 2 to get the array index.
+	SubstituteNameOffset uint16
+	// The integer that contains the length, in bytes, of the
+	// substitute name string. If this string is null-terminated,
+	// SubstituteNameLength does not include the Unicode null character.
+	SubstituteNameLength uint16
+	// PrintNameOffset is similar to SubstituteNameOffset.
+	PrintNameOffset uint16
+	// PrintNameLength is similar to SubstituteNameLength.
+	PrintNameLength uint16
+	PathBuffer      [1]uint16
+}
+
+// Path returns path stored in rb.
+func (rb *MountPointReparseBuffer) Path() string {
+	n1 := rb.SubstituteNameOffset / 2
+	n2 := (rb.SubstituteNameOffset + rb.SubstituteNameLength) / 2
+	return syscall.UTF16ToString((*[0xffff]uint16)(unsafe.Pointer(&rb.PathBuffer[0]))[n1:n2:n2])
+}
diff --git a/contrib/go/_std_1.20/src/internal/syscall/windows/security_windows.go b/contrib/go/_std_1.20/src/internal/syscall/windows/security_windows.go
new file mode 100644
index 0000000000..4a2dfc0c73
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/windows/security_windows.go
@@ -0,0 +1,128 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package windows
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+const (
+	SecurityAnonymous      = 0
+	SecurityIdentification = 1
+	SecurityImpersonation  = 2
+	SecurityDelegation     = 3
+)
+
+//sys	ImpersonateSelf(impersonationlevel uint32) (err error) = advapi32.ImpersonateSelf
+//sys	RevertToSelf() (err error) = advapi32.RevertToSelf
+
+const (
+	TOKEN_ADJUST_PRIVILEGES = 0x0020
+	SE_PRIVILEGE_ENABLED    = 0x00000002
+)
+
+type LUID struct {
+	LowPart  uint32
+	HighPart int32
+}
+
+type LUID_AND_ATTRIBUTES struct {
+	Luid       LUID
+	Attributes uint32
+}
+
+type TOKEN_PRIVILEGES struct {
+	PrivilegeCount uint32
+	Privileges     [1]LUID_AND_ATTRIBUTES
+}
+
+//sys	OpenThreadToken(h syscall.Handle, access uint32, openasself bool, token *syscall.Token) (err error) = advapi32.OpenThreadToken
+//sys	LookupPrivilegeValue(systemname *uint16, name *uint16, luid *LUID) (err error) = advapi32.LookupPrivilegeValueW
+//sys	adjustTokenPrivileges(token syscall.Token, disableAllPrivileges bool, newstate *TOKEN_PRIVILEGES, buflen uint32, prevstate *TOKEN_PRIVILEGES, returnlen *uint32) (ret uint32, err error) [true] = advapi32.AdjustTokenPrivileges
+
+func AdjustTokenPrivileges(token syscall.Token, disableAllPrivileges bool, newstate *TOKEN_PRIVILEGES, buflen uint32, prevstate *TOKEN_PRIVILEGES, returnlen *uint32) error {
+	ret, err := adjustTokenPrivileges(token, disableAllPrivileges, newstate, buflen, prevstate, returnlen)
+	if ret == 0 {
+		// AdjustTokenPrivileges call failed
+		return err
+	}
+	// AdjustTokenPrivileges call succeeded
+	if err == syscall.EINVAL {
+		// GetLastError returned ERROR_SUCCESS
+		return nil
+	}
+	return err
+}
+
+//sys DuplicateTokenEx(hExistingToken syscall.Token, dwDesiredAccess uint32, lpTokenAttributes *syscall.SecurityAttributes, impersonationLevel uint32, tokenType TokenType, phNewToken *syscall.Token) (err error) = advapi32.DuplicateTokenEx
+//sys SetTokenInformation(tokenHandle syscall.Token, tokenInformationClass uint32, tokenInformation uintptr, tokenInformationLength uint32) (err error) = advapi32.SetTokenInformation
+
+type SID_AND_ATTRIBUTES struct {
+	Sid        *syscall.SID
+	Attributes uint32
+}
+
+type TOKEN_MANDATORY_LABEL struct {
+	Label SID_AND_ATTRIBUTES
+}
+
+func (tml *TOKEN_MANDATORY_LABEL) Size() uint32 {
+	return uint32(unsafe.Sizeof(TOKEN_MANDATORY_LABEL{})) + syscall.GetLengthSid(tml.Label.Sid)
+}
+
+const SE_GROUP_INTEGRITY = 0x00000020
+
+type TokenType uint32
+
+const (
+	TokenPrimary       TokenType = 1
+	TokenImpersonation TokenType = 2
+)
+
+//sys	GetProfilesDirectory(dir *uint16, dirLen *uint32) (err error) = userenv.GetProfilesDirectoryW
+
+const (
+	LG_INCLUDE_INDIRECT  = 0x1
+	MAX_PREFERRED_LENGTH = 0xFFFFFFFF
+)
+
+type LocalGroupUserInfo0 struct {
+	Name *uint16
+}
+
+type UserInfo4 struct {
+	Name            *uint16
+	Password        *uint16
+	PasswordAge     uint32
+	Priv            uint32
+	HomeDir         *uint16
+	Comment         *uint16
+	Flags           uint32
+	ScriptPath      *uint16
+	AuthFlags       uint32
+	FullName        *uint16
+	UsrComment      *uint16
+	Parms           *uint16
+	Workstations    *uint16
+	LastLogon       uint32
+	LastLogoff      uint32
+	AcctExpires     uint32
+	MaxStorage      uint32
+	UnitsPerWeek    uint32
+	LogonHours      *byte
+	BadPwCount      uint32
+	NumLogons       uint32
+	LogonServer     *uint16
+	CountryCode     uint32
+	CodePage        uint32
+	UserSid         *syscall.SID
+	PrimaryGroupID  uint32
+	Profile         *uint16
+	HomeDirDrive    *uint16
+	PasswordExpired uint32
+}
+
+//sys	NetUserGetLocalGroups(serverName *uint16, userName *uint16, level uint32, flags uint32, buf **byte, prefMaxLen uint32, entriesRead *uint32, totalEntries *uint32) (neterr error) = netapi32.NetUserGetLocalGroups
diff --git a/contrib/go/_std_1.20/src/internal/syscall/windows/symlink_windows.go b/contrib/go/_std_1.20/src/internal/syscall/windows/symlink_windows.go
new file mode 100644
index 0000000000..b64d058d13
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/windows/symlink_windows.go
@@ -0,0 +1,39 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package windows
+
+import "syscall"
+
+const (
+	ERROR_INVALID_PARAMETER syscall.Errno = 87
+
+	// symlink support for CreateSymbolicLink() starting with Windows 10 (1703, v10.0.14972)
+	SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE = 0x2
+
+	// FileInformationClass values
+	FileBasicInfo                  = 0    // FILE_BASIC_INFO
+	FileStandardInfo               = 1    // FILE_STANDARD_INFO
+	FileNameInfo                   = 2    // FILE_NAME_INFO
+	FileStreamInfo                 = 7    // FILE_STREAM_INFO
+	FileCompressionInfo            = 8    // FILE_COMPRESSION_INFO
+	FileAttributeTagInfo           = 9    // FILE_ATTRIBUTE_TAG_INFO
+	FileIdBothDirectoryInfo        = 0xa  // FILE_ID_BOTH_DIR_INFO
+	FileIdBothDirectoryRestartInfo = 0xb  // FILE_ID_BOTH_DIR_INFO
+	FileRemoteProtocolInfo         = 0xd  // FILE_REMOTE_PROTOCOL_INFO
+	FileFullDirectoryInfo          = 0xe  // FILE_FULL_DIR_INFO
+	FileFullDirectoryRestartInfo   = 0xf  // FILE_FULL_DIR_INFO
+	FileStorageInfo                = 0x10 // FILE_STORAGE_INFO
+	FileAlignmentInfo              = 0x11 // FILE_ALIGNMENT_INFO
+	FileIdInfo                     = 0x12 // FILE_ID_INFO
+	FileIdExtdDirectoryInfo        = 0x13 // FILE_ID_EXTD_DIR_INFO
+	FileIdExtdDirectoryRestartInfo = 0x14 // FILE_ID_EXTD_DIR_INFO
+)
+
+type FILE_ATTRIBUTE_TAG_INFO struct {
+	FileAttributes uint32
+	ReparseTag     uint32
+}
+
+//sys	GetFileInformationByHandleEx(handle syscall.Handle, class uint32, info *byte, bufsize uint32) (err error)
diff --git a/contrib/go/_std_1.20/src/internal/syscall/windows/syscall_windows.go b/contrib/go/_std_1.20/src/internal/syscall/windows/syscall_windows.go
new file mode 100644
index 0000000000..8ace2a27e7
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/windows/syscall_windows.go
@@ -0,0 +1,369 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package windows
+
+import (
+	"sync"
+	"syscall"
+	"unicode/utf16"
+	"unsafe"
+)
+
+// UTF16PtrToString is like UTF16ToString, but takes *uint16
+// as a parameter instead of []uint16.
+func UTF16PtrToString(p *uint16) string {
+	if p == nil {
+		return ""
+	}
+	// Find NUL terminator.
+	end := unsafe.Pointer(p)
+	n := 0
+	for *(*uint16)(end) != 0 {
+		end = unsafe.Pointer(uintptr(end) + unsafe.Sizeof(*p))
+		n++
+	}
+	// Turn *uint16 into []uint16.
+	s := unsafe.Slice(p, n)
+	// Decode []uint16 into string.
+	return string(utf16.Decode(s))
+}
+
+const (
+	ERROR_BAD_LENGTH             syscall.Errno = 24
+	ERROR_SHARING_VIOLATION      syscall.Errno = 32
+	ERROR_LOCK_VIOLATION         syscall.Errno = 33
+	ERROR_NOT_SUPPORTED          syscall.Errno = 50
+	ERROR_CALL_NOT_IMPLEMENTED   syscall.Errno = 120
+	ERROR_INVALID_NAME           syscall.Errno = 123
+	ERROR_LOCK_FAILED            syscall.Errno = 167
+	ERROR_NO_UNICODE_TRANSLATION syscall.Errno = 1113
+)
+
+const GAA_FLAG_INCLUDE_PREFIX = 0x00000010
+
+const (
+	IF_TYPE_OTHER              = 1
+	IF_TYPE_ETHERNET_CSMACD    = 6
+	IF_TYPE_ISO88025_TOKENRING = 9
+	IF_TYPE_PPP                = 23
+	IF_TYPE_SOFTWARE_LOOPBACK  = 24
+	IF_TYPE_ATM                = 37
+	IF_TYPE_IEEE80211          = 71
+	IF_TYPE_TUNNEL             = 131
+	IF_TYPE_IEEE1394           = 144
+)
+
+type SocketAddress struct {
+	Sockaddr       *syscall.RawSockaddrAny
+	SockaddrLength int32
+}
+
+type IpAdapterUnicastAddress struct {
+	Length             uint32
+	Flags              uint32
+	Next               *IpAdapterUnicastAddress
+	Address            SocketAddress
+	PrefixOrigin       int32
+	SuffixOrigin       int32
+	DadState           int32
+	ValidLifetime      uint32
+	PreferredLifetime  uint32
+	LeaseLifetime      uint32
+	OnLinkPrefixLength uint8
+}
+
+type IpAdapterAnycastAddress struct {
+	Length  uint32
+	Flags   uint32
+	Next    *IpAdapterAnycastAddress
+	Address SocketAddress
+}
+
+type IpAdapterMulticastAddress struct {
+	Length  uint32
+	Flags   uint32
+	Next    *IpAdapterMulticastAddress
+	Address SocketAddress
+}
+
+type IpAdapterDnsServerAdapter struct {
+	Length   uint32
+	Reserved uint32
+	Next     *IpAdapterDnsServerAdapter
+	Address  SocketAddress
+}
+
+type IpAdapterPrefix struct {
+	Length       uint32
+	Flags        uint32
+	Next         *IpAdapterPrefix
+	Address      SocketAddress
+	PrefixLength uint32
+}
+
+type IpAdapterAddresses struct {
+	Length                uint32
+	IfIndex               uint32
+	Next                  *IpAdapterAddresses
+	AdapterName           *byte
+	FirstUnicastAddress   *IpAdapterUnicastAddress
+	FirstAnycastAddress   *IpAdapterAnycastAddress
+	FirstMulticastAddress *IpAdapterMulticastAddress
+	FirstDnsServerAddress *IpAdapterDnsServerAdapter
+	DnsSuffix             *uint16
+	Description           *uint16
+	FriendlyName          *uint16
+	PhysicalAddress       [syscall.MAX_ADAPTER_ADDRESS_LENGTH]byte
+	PhysicalAddressLength uint32
+	Flags                 uint32
+	Mtu                   uint32
+	IfType                uint32
+	OperStatus            uint32
+	Ipv6IfIndex           uint32
+	ZoneIndices           [16]uint32
+	FirstPrefix           *IpAdapterPrefix
+	/* more fields might be present here. */
+}
+
+type FILE_BASIC_INFO struct {
+	CreationTime   syscall.Filetime
+	LastAccessTime syscall.Filetime
+	LastWriteTime  syscall.Filetime
+	ChangedTime    syscall.Filetime
+	FileAttributes uint32
+}
+
+const (
+	IfOperStatusUp             = 1
+	IfOperStatusDown           = 2
+	IfOperStatusTesting        = 3
+	IfOperStatusUnknown        = 4
+	IfOperStatusDormant        = 5
+	IfOperStatusNotPresent     = 6
+	IfOperStatusLowerLayerDown = 7
+)
+
+//sys	GetAdaptersAddresses(family uint32, flags uint32, reserved uintptr, adapterAddresses *IpAdapterAddresses, sizePointer *uint32) (errcode error) = iphlpapi.GetAdaptersAddresses
+//sys	GetComputerNameEx(nameformat uint32, buf *uint16, n *uint32) (err error) = GetComputerNameExW
+//sys	MoveFileEx(from *uint16, to *uint16, flags uint32) (err error) = MoveFileExW
+//sys	GetModuleFileName(module syscall.Handle, fn *uint16, len uint32) (n uint32, err error) = kernel32.GetModuleFileNameW
+//sys	SetFileInformationByHandle(handle syscall.Handle, fileInformationClass uint32, buf uintptr, bufsize uint32) (err error) = kernel32.SetFileInformationByHandle
+//sys	VirtualQuery(address uintptr, buffer *MemoryBasicInformation, length uintptr) (err error) = kernel32.VirtualQuery
+
+const (
+	// flags for CreateToolhelp32Snapshot
+	TH32CS_SNAPMODULE   = 0x08
+	TH32CS_SNAPMODULE32 = 0x10
+)
+
+const MAX_MODULE_NAME32 = 255
+
+type ModuleEntry32 struct {
+	Size         uint32
+	ModuleID     uint32
+	ProcessID    uint32
+	GlblcntUsage uint32
+	ProccntUsage uint32
+	ModBaseAddr  uintptr
+	ModBaseSize  uint32
+	ModuleHandle syscall.Handle
+	Module       [MAX_MODULE_NAME32 + 1]uint16
+	ExePath      [syscall.MAX_PATH]uint16
+}
+
+const SizeofModuleEntry32 = unsafe.Sizeof(ModuleEntry32{})
+
+//sys	Module32First(snapshot syscall.Handle, moduleEntry *ModuleEntry32) (err error) = kernel32.Module32FirstW
+//sys	Module32Next(snapshot syscall.Handle, moduleEntry *ModuleEntry32) (err error) = kernel32.Module32NextW
+
+const (
+	WSA_FLAG_OVERLAPPED        = 0x01
+	WSA_FLAG_NO_HANDLE_INHERIT = 0x80
+
+	WSAEMSGSIZE syscall.Errno = 10040
+
+	MSG_PEEK   = 0x2
+	MSG_TRUNC  = 0x0100
+	MSG_CTRUNC = 0x0200
+
+	socket_error = uintptr(^uint32(0))
+)
+
+var WSAID_WSASENDMSG = syscall.GUID{
+	Data1: 0xa441e712,
+	Data2: 0x754f,
+	Data3: 0x43ca,
+	Data4: [8]byte{0x84, 0xa7, 0x0d, 0xee, 0x44, 0xcf, 0x60, 0x6d},
+}
+
+var WSAID_WSARECVMSG = syscall.GUID{
+	Data1: 0xf689d7c8,
+	Data2: 0x6f1f,
+	Data3: 0x436b,
+	Data4: [8]byte{0x8a, 0x53, 0xe5, 0x4f, 0xe3, 0x51, 0xc3, 0x22},
+}
+
+var sendRecvMsgFunc struct {
+	once     sync.Once
+	sendAddr uintptr
+	recvAddr uintptr
+	err      error
+}
+
+type WSAMsg struct {
+	Name        syscall.Pointer
+	Namelen     int32
+	Buffers     *syscall.WSABuf
+	BufferCount uint32
+	Control     syscall.WSABuf
+	Flags       uint32
+}
+
+//sys	WSASocket(af int32, typ int32, protocol int32, protinfo *syscall.WSAProtocolInfo, group uint32, flags uint32) (handle syscall.Handle, err error) [failretval==syscall.InvalidHandle] = ws2_32.WSASocketW
+
+func loadWSASendRecvMsg() error {
+	sendRecvMsgFunc.once.Do(func() {
+		var s syscall.Handle
+		s, sendRecvMsgFunc.err = syscall.Socket(syscall.AF_INET, syscall.SOCK_DGRAM, syscall.IPPROTO_UDP)
+		if sendRecvMsgFunc.err != nil {
+			return
+		}
+		defer syscall.CloseHandle(s)
+		var n uint32
+		sendRecvMsgFunc.err = syscall.WSAIoctl(s,
+			syscall.SIO_GET_EXTENSION_FUNCTION_POINTER,
+			(*byte)(unsafe.Pointer(&WSAID_WSARECVMSG)),
+			uint32(unsafe.Sizeof(WSAID_WSARECVMSG)),
+			(*byte)(unsafe.Pointer(&sendRecvMsgFunc.recvAddr)),
+			uint32(unsafe.Sizeof(sendRecvMsgFunc.recvAddr)),
+			&n, nil, 0)
+		if sendRecvMsgFunc.err != nil {
+			return
+		}
+		sendRecvMsgFunc.err = syscall.WSAIoctl(s,
+			syscall.SIO_GET_EXTENSION_FUNCTION_POINTER,
+			(*byte)(unsafe.Pointer(&WSAID_WSASENDMSG)),
+			uint32(unsafe.Sizeof(WSAID_WSASENDMSG)),
+			(*byte)(unsafe.Pointer(&sendRecvMsgFunc.sendAddr)),
+			uint32(unsafe.Sizeof(sendRecvMsgFunc.sendAddr)),
+			&n, nil, 0)
+	})
+	return sendRecvMsgFunc.err
+}
+
+func WSASendMsg(fd syscall.Handle, msg *WSAMsg, flags uint32, bytesSent *uint32, overlapped *syscall.Overlapped, croutine *byte) error {
+	err := loadWSASendRecvMsg()
+	if err != nil {
+		return err
+	}
+	r1, _, e1 := syscall.Syscall6(sendRecvMsgFunc.sendAddr, 6, uintptr(fd), uintptr(unsafe.Pointer(msg)), uintptr(flags), uintptr(unsafe.Pointer(bytesSent)), uintptr(unsafe.Pointer(overlapped)), uintptr(unsafe.Pointer(croutine)))
+	if r1 == socket_error {
+		if e1 != 0 {
+			err = errnoErr(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return err
+}
+
+func WSARecvMsg(fd syscall.Handle, msg *WSAMsg, bytesReceived *uint32, overlapped *syscall.Overlapped, croutine *byte) error {
+	err := loadWSASendRecvMsg()
+	if err != nil {
+		return err
+	}
+	r1, _, e1 := syscall.Syscall6(sendRecvMsgFunc.recvAddr, 5, uintptr(fd), uintptr(unsafe.Pointer(msg)), uintptr(unsafe.Pointer(bytesReceived)), uintptr(unsafe.Pointer(overlapped)), uintptr(unsafe.Pointer(croutine)), 0)
+	if r1 == socket_error {
+		if e1 != 0 {
+			err = errnoErr(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return err
+}
+
+const (
+	ComputerNameNetBIOS                   = 0
+	ComputerNameDnsHostname               = 1
+	ComputerNameDnsDomain                 = 2
+	ComputerNameDnsFullyQualified         = 3
+	ComputerNamePhysicalNetBIOS           = 4
+	ComputerNamePhysicalDnsHostname       = 5
+	ComputerNamePhysicalDnsDomain         = 6
+	ComputerNamePhysicalDnsFullyQualified = 7
+	ComputerNameMax                       = 8
+
+	MOVEFILE_REPLACE_EXISTING      = 0x1
+	MOVEFILE_COPY_ALLOWED          = 0x2
+	MOVEFILE_DELAY_UNTIL_REBOOT    = 0x4
+	MOVEFILE_WRITE_THROUGH         = 0x8
+	MOVEFILE_CREATE_HARDLINK       = 0x10
+	MOVEFILE_FAIL_IF_NOT_TRACKABLE = 0x20
+)
+
+func Rename(oldpath, newpath string) error {
+	from, err := syscall.UTF16PtrFromString(oldpath)
+	if err != nil {
+		return err
+	}
+	to, err := syscall.UTF16PtrFromString(newpath)
+	if err != nil {
+		return err
+	}
+	return MoveFileEx(from, to, MOVEFILE_REPLACE_EXISTING)
+}
+
+//sys LockFileEx(file syscall.Handle, flags uint32, reserved uint32, bytesLow uint32, bytesHigh uint32, overlapped *syscall.Overlapped) (err error) = kernel32.LockFileEx
+//sys UnlockFileEx(file syscall.Handle, reserved uint32, bytesLow uint32, bytesHigh uint32, overlapped *syscall.Overlapped) (err error) = kernel32.UnlockFileEx
+
+const (
+	LOCKFILE_FAIL_IMMEDIATELY = 0x00000001
+	LOCKFILE_EXCLUSIVE_LOCK   = 0x00000002
+)
+
+const MB_ERR_INVALID_CHARS = 8
+
+//sys	GetACP() (acp uint32) = kernel32.GetACP
+//sys	GetConsoleCP() (ccp uint32) = kernel32.GetConsoleCP
+//sys	MultiByteToWideChar(codePage uint32, dwFlags uint32, str *byte, nstr int32, wchar *uint16, nwchar int32) (nwrite int32, err error) = kernel32.MultiByteToWideChar
+//sys	GetCurrentThread() (pseudoHandle syscall.Handle, err error) = kernel32.GetCurrentThread
+
+const STYPE_DISKTREE = 0x00
+
+type SHARE_INFO_2 struct {
+	Netname     *uint16
+	Type        uint32
+	Remark      *uint16
+	Permissions uint32
+	MaxUses     uint32
+	CurrentUses uint32
+	Path        *uint16
+	Passwd      *uint16
+}
+
+//sys  NetShareAdd(serverName *uint16, level uint32, buf *byte, parmErr *uint16) (neterr error) = netapi32.NetShareAdd
+//sys  NetShareDel(serverName *uint16, netName *uint16, reserved uint32) (neterr error) = netapi32.NetShareDel
+
+const (
+	FILE_NAME_NORMALIZED = 0x0
+	FILE_NAME_OPENED     = 0x8
+
+	VOLUME_NAME_DOS  = 0x0
+	VOLUME_NAME_GUID = 0x1
+	VOLUME_NAME_NONE = 0x4
+	VOLUME_NAME_NT   = 0x2
+)
+
+//sys	GetFinalPathNameByHandle(file syscall.Handle, filePath *uint16, filePathSize uint32, flags uint32) (n uint32, err error) = kernel32.GetFinalPathNameByHandleW
+
+func LoadGetFinalPathNameByHandle() error {
+	return procGetFinalPathNameByHandleW.Find()
+}
+
+//sys	CreateEnvironmentBlock(block **uint16, token syscall.Token, inheritExisting bool) (err error) = userenv.CreateEnvironmentBlock
+//sys	DestroyEnvironmentBlock(block *uint16) (err error) = userenv.DestroyEnvironmentBlock
+
+//sys	RtlGenRandom(buf []byte) (err error) = advapi32.SystemFunction036
diff --git a/contrib/go/_std_1.20/src/internal/syscall/windows/sysdll/sysdll.go b/contrib/go/_std_1.20/src/internal/syscall/windows/sysdll/sysdll.go
new file mode 100644
index 0000000000..e79fd19edc
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/windows/sysdll/sysdll.go
@@ -0,0 +1,30 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build windows
+
+// Package sysdll is an internal leaf package that records and reports
+// which Windows DLL names are used by Go itself. These DLLs are then
+// only loaded from the System32 directory. See Issue 14959.
+package sysdll
+
+// IsSystemDLL reports whether the named dll key (a base name, like
+// "foo.dll") is a system DLL which should only be loaded from the
+// Windows SYSTEM32 directory.
+//
+// Filenames are case sensitive, but that doesn't matter because
+// the case registered with Add is also the same case used with
+// LoadDLL later.
+//
+// It has no associated mutex and should only be mutated serially
+// (currently: during init), and not concurrent with DLL loading.
+var IsSystemDLL = map[string]bool{}
+
+// Add notes that dll is a system32 DLL which should only be loaded
+// from the Windows SYSTEM32 directory. It returns its argument back,
+// for ease of use in generated code.
+func Add(dll string) string {
+	IsSystemDLL[dll] = true
+	return dll
+}
diff --git a/contrib/go/_std_1.20/src/internal/syscall/windows/sysdll/ya.make b/contrib/go/_std_1.20/src/internal/syscall/windows/sysdll/ya.make
new file mode 100644
index 0000000000..7f2cd0fe71
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/windows/sysdll/ya.make
@@ -0,0 +1,11 @@
+GO_LIBRARY()
+
+BUILD_ONLY_IF(WARNING OS_WINDOWS)
+
+IF (OS_WINDOWS)
+    SRCS(
+        sysdll.go
+    )
+ENDIF()
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/syscall/windows/ya.make b/contrib/go/_std_1.20/src/internal/syscall/windows/ya.make
new file mode 100644
index 0000000000..34b9e2d231
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/windows/ya.make
@@ -0,0 +1,25 @@
+GO_LIBRARY()
+
+BUILD_ONLY_IF(WARNING OS_WINDOWS)
+
+IF (OS_WINDOWS)
+    SRCS(
+        memory_windows.go
+        net_windows.go
+        psapi_windows.go
+        reparse_windows.go
+        security_windows.go
+        symlink_windows.go
+        syscall_windows.go
+        zsyscall_windows.go
+    )
+ENDIF()
+
+END()
+
+IF (OS_WINDOWS)
+    RECURSE(
+        registry
+        sysdll
+    )
+ENDIF()
diff --git a/contrib/go/_std_1.20/src/internal/syscall/windows/zsyscall_windows.go b/contrib/go/_std_1.20/src/internal/syscall/windows/zsyscall_windows.go
new file mode 100644
index 0000000000..afd64e318e
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/syscall/windows/zsyscall_windows.go
@@ -0,0 +1,354 @@
+// Code generated by 'go generate'; DO NOT EDIT.
+
+package windows
+
+import (
+	"internal/syscall/windows/sysdll"
+	"syscall"
+	"unsafe"
+)
+
+var _ unsafe.Pointer
+
+// Do the interface allocations only once for common
+// Errno values.
+const (
+	errnoERROR_IO_PENDING = 997
+)
+
+var (
+	errERROR_IO_PENDING error = syscall.Errno(errnoERROR_IO_PENDING)
+	errERROR_EINVAL     error = syscall.EINVAL
+)
+
+// errnoErr returns common boxed Errno values, to prevent
+// allocations at runtime.
+func errnoErr(e syscall.Errno) error {
+	switch e {
+	case 0:
+		return errERROR_EINVAL
+	case errnoERROR_IO_PENDING:
+		return errERROR_IO_PENDING
+	}
+	// TODO: add more here, after collecting data on the common
+	// error values see on Windows. (perhaps when running
+	// all.bat?)
+	return e
+}
+
+var (
+	modadvapi32 = syscall.NewLazyDLL(sysdll.Add("advapi32.dll"))
+	modiphlpapi = syscall.NewLazyDLL(sysdll.Add("iphlpapi.dll"))
+	modkernel32 = syscall.NewLazyDLL(sysdll.Add("kernel32.dll"))
+	modnetapi32 = syscall.NewLazyDLL(sysdll.Add("netapi32.dll"))
+	modpsapi    = syscall.NewLazyDLL(sysdll.Add("psapi.dll"))
+	moduserenv  = syscall.NewLazyDLL(sysdll.Add("userenv.dll"))
+	modws2_32   = syscall.NewLazyDLL(sysdll.Add("ws2_32.dll"))
+
+	procAdjustTokenPrivileges        = modadvapi32.NewProc("AdjustTokenPrivileges")
+	procDuplicateTokenEx             = modadvapi32.NewProc("DuplicateTokenEx")
+	procImpersonateSelf              = modadvapi32.NewProc("ImpersonateSelf")
+	procLookupPrivilegeValueW        = modadvapi32.NewProc("LookupPrivilegeValueW")
+	procOpenThreadToken              = modadvapi32.NewProc("OpenThreadToken")
+	procRevertToSelf                 = modadvapi32.NewProc("RevertToSelf")
+	procSetTokenInformation          = modadvapi32.NewProc("SetTokenInformation")
+	procSystemFunction036            = modadvapi32.NewProc("SystemFunction036")
+	procGetAdaptersAddresses         = modiphlpapi.NewProc("GetAdaptersAddresses")
+	procGetACP                       = modkernel32.NewProc("GetACP")
+	procGetComputerNameExW           = modkernel32.NewProc("GetComputerNameExW")
+	procGetConsoleCP                 = modkernel32.NewProc("GetConsoleCP")
+	procGetCurrentThread             = modkernel32.NewProc("GetCurrentThread")
+	procGetFileInformationByHandleEx = modkernel32.NewProc("GetFileInformationByHandleEx")
+	procGetFinalPathNameByHandleW    = modkernel32.NewProc("GetFinalPathNameByHandleW")
+	procGetModuleFileNameW           = modkernel32.NewProc("GetModuleFileNameW")
+	procLockFileEx                   = modkernel32.NewProc("LockFileEx")
+	procModule32FirstW               = modkernel32.NewProc("Module32FirstW")
+	procModule32NextW                = modkernel32.NewProc("Module32NextW")
+	procMoveFileExW                  = modkernel32.NewProc("MoveFileExW")
+	procMultiByteToWideChar          = modkernel32.NewProc("MultiByteToWideChar")
+	procSetFileInformationByHandle   = modkernel32.NewProc("SetFileInformationByHandle")
+	procUnlockFileEx                 = modkernel32.NewProc("UnlockFileEx")
+	procVirtualQuery                 = modkernel32.NewProc("VirtualQuery")
+	procNetShareAdd                  = modnetapi32.NewProc("NetShareAdd")
+	procNetShareDel                  = modnetapi32.NewProc("NetShareDel")
+	procNetUserGetLocalGroups        = modnetapi32.NewProc("NetUserGetLocalGroups")
+	procGetProcessMemoryInfo         = modpsapi.NewProc("GetProcessMemoryInfo")
+	procCreateEnvironmentBlock       = moduserenv.NewProc("CreateEnvironmentBlock")
+	procDestroyEnvironmentBlock      = moduserenv.NewProc("DestroyEnvironmentBlock")
+	procGetProfilesDirectoryW        = moduserenv.NewProc("GetProfilesDirectoryW")
+	procWSASocketW                   = modws2_32.NewProc("WSASocketW")
+)
+
+func adjustTokenPrivileges(token syscall.Token, disableAllPrivileges bool, newstate *TOKEN_PRIVILEGES, buflen uint32, prevstate *TOKEN_PRIVILEGES, returnlen *uint32) (ret uint32, err error) {
+	var _p0 uint32
+	if disableAllPrivileges {
+		_p0 = 1
+	}
+	r0, _, e1 := syscall.Syscall6(procAdjustTokenPrivileges.Addr(), 6, uintptr(token), uintptr(_p0), uintptr(unsafe.Pointer(newstate)), uintptr(buflen), uintptr(unsafe.Pointer(prevstate)), uintptr(unsafe.Pointer(returnlen)))
+	ret = uint32(r0)
+	if true {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func DuplicateTokenEx(hExistingToken syscall.Token, dwDesiredAccess uint32, lpTokenAttributes *syscall.SecurityAttributes, impersonationLevel uint32, tokenType TokenType, phNewToken *syscall.Token) (err error) {
+	r1, _, e1 := syscall.Syscall6(procDuplicateTokenEx.Addr(), 6, uintptr(hExistingToken), uintptr(dwDesiredAccess), uintptr(unsafe.Pointer(lpTokenAttributes)), uintptr(impersonationLevel), uintptr(tokenType), uintptr(unsafe.Pointer(phNewToken)))
+	if r1 == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func ImpersonateSelf(impersonationlevel uint32) (err error) {
+	r1, _, e1 := syscall.Syscall(procImpersonateSelf.Addr(), 1, uintptr(impersonationlevel), 0, 0)
+	if r1 == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func LookupPrivilegeValue(systemname *uint16, name *uint16, luid *LUID) (err error) {
+	r1, _, e1 := syscall.Syscall(procLookupPrivilegeValueW.Addr(), 3, uintptr(unsafe.Pointer(systemname)), uintptr(unsafe.Pointer(name)), uintptr(unsafe.Pointer(luid)))
+	if r1 == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func OpenThreadToken(h syscall.Handle, access uint32, openasself bool, token *syscall.Token) (err error) {
+	var _p0 uint32
+	if openasself {
+		_p0 = 1
+	}
+	r1, _, e1 := syscall.Syscall6(procOpenThreadToken.Addr(), 4, uintptr(h), uintptr(access), uintptr(_p0), uintptr(unsafe.Pointer(token)), 0, 0)
+	if r1 == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func RevertToSelf() (err error) {
+	r1, _, e1 := syscall.Syscall(procRevertToSelf.Addr(), 0, 0, 0, 0)
+	if r1 == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func SetTokenInformation(tokenHandle syscall.Token, tokenInformationClass uint32, tokenInformation uintptr, tokenInformationLength uint32) (err error) {
+	r1, _, e1 := syscall.Syscall6(procSetTokenInformation.Addr(), 4, uintptr(tokenHandle), uintptr(tokenInformationClass), uintptr(tokenInformation), uintptr(tokenInformationLength), 0, 0)
+	if r1 == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func RtlGenRandom(buf []byte) (err error) {
+	var _p0 *byte
+	if len(buf) > 0 {
+		_p0 = &buf[0]
+	}
+	r1, _, e1 := syscall.Syscall(procSystemFunction036.Addr(), 2, uintptr(unsafe.Pointer(_p0)), uintptr(len(buf)), 0)
+	if r1 == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func GetAdaptersAddresses(family uint32, flags uint32, reserved uintptr, adapterAddresses *IpAdapterAddresses, sizePointer *uint32) (errcode error) {
+	r0, _, _ := syscall.Syscall6(procGetAdaptersAddresses.Addr(), 5, uintptr(family), uintptr(flags), uintptr(reserved), uintptr(unsafe.Pointer(adapterAddresses)), uintptr(unsafe.Pointer(sizePointer)), 0)
+	if r0 != 0 {
+		errcode = syscall.Errno(r0)
+	}
+	return
+}
+
+func GetACP() (acp uint32) {
+	r0, _, _ := syscall.Syscall(procGetACP.Addr(), 0, 0, 0, 0)
+	acp = uint32(r0)
+	return
+}
+
+func GetComputerNameEx(nameformat uint32, buf *uint16, n *uint32) (err error) {
+	r1, _, e1 := syscall.Syscall(procGetComputerNameExW.Addr(), 3, uintptr(nameformat), uintptr(unsafe.Pointer(buf)), uintptr(unsafe.Pointer(n)))
+	if r1 == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func GetConsoleCP() (ccp uint32) {
+	r0, _, _ := syscall.Syscall(procGetConsoleCP.Addr(), 0, 0, 0, 0)
+	ccp = uint32(r0)
+	return
+}
+
+func GetCurrentThread() (pseudoHandle syscall.Handle, err error) {
+	r0, _, e1 := syscall.Syscall(procGetCurrentThread.Addr(), 0, 0, 0, 0)
+	pseudoHandle = syscall.Handle(r0)
+	if pseudoHandle == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func GetFileInformationByHandleEx(handle syscall.Handle, class uint32, info *byte, bufsize uint32) (err error) {
+	r1, _, e1 := syscall.Syscall6(procGetFileInformationByHandleEx.Addr(), 4, uintptr(handle), uintptr(class), uintptr(unsafe.Pointer(info)), uintptr(bufsize), 0, 0)
+	if r1 == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func GetFinalPathNameByHandle(file syscall.Handle, filePath *uint16, filePathSize uint32, flags uint32) (n uint32, err error) {
+	r0, _, e1 := syscall.Syscall6(procGetFinalPathNameByHandleW.Addr(), 4, uintptr(file), uintptr(unsafe.Pointer(filePath)), uintptr(filePathSize), uintptr(flags), 0, 0)
+	n = uint32(r0)
+	if n == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func GetModuleFileName(module syscall.Handle, fn *uint16, len uint32) (n uint32, err error) {
+	r0, _, e1 := syscall.Syscall(procGetModuleFileNameW.Addr(), 3, uintptr(module), uintptr(unsafe.Pointer(fn)), uintptr(len))
+	n = uint32(r0)
+	if n == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func LockFileEx(file syscall.Handle, flags uint32, reserved uint32, bytesLow uint32, bytesHigh uint32, overlapped *syscall.Overlapped) (err error) {
+	r1, _, e1 := syscall.Syscall6(procLockFileEx.Addr(), 6, uintptr(file), uintptr(flags), uintptr(reserved), uintptr(bytesLow), uintptr(bytesHigh), uintptr(unsafe.Pointer(overlapped)))
+	if r1 == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func Module32First(snapshot syscall.Handle, moduleEntry *ModuleEntry32) (err error) {
+	r1, _, e1 := syscall.Syscall(procModule32FirstW.Addr(), 2, uintptr(snapshot), uintptr(unsafe.Pointer(moduleEntry)), 0)
+	if r1 == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func Module32Next(snapshot syscall.Handle, moduleEntry *ModuleEntry32) (err error) {
+	r1, _, e1 := syscall.Syscall(procModule32NextW.Addr(), 2, uintptr(snapshot), uintptr(unsafe.Pointer(moduleEntry)), 0)
+	if r1 == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func MoveFileEx(from *uint16, to *uint16, flags uint32) (err error) {
+	r1, _, e1 := syscall.Syscall(procMoveFileExW.Addr(), 3, uintptr(unsafe.Pointer(from)), uintptr(unsafe.Pointer(to)), uintptr(flags))
+	if r1 == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func MultiByteToWideChar(codePage uint32, dwFlags uint32, str *byte, nstr int32, wchar *uint16, nwchar int32) (nwrite int32, err error) {
+	r0, _, e1 := syscall.Syscall6(procMultiByteToWideChar.Addr(), 6, uintptr(codePage), uintptr(dwFlags), uintptr(unsafe.Pointer(str)), uintptr(nstr), uintptr(unsafe.Pointer(wchar)), uintptr(nwchar))
+	nwrite = int32(r0)
+	if nwrite == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func SetFileInformationByHandle(handle syscall.Handle, fileInformationClass uint32, buf uintptr, bufsize uint32) (err error) {
+	r1, _, e1 := syscall.Syscall6(procSetFileInformationByHandle.Addr(), 4, uintptr(handle), uintptr(fileInformationClass), uintptr(buf), uintptr(bufsize), 0, 0)
+	if r1 == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func UnlockFileEx(file syscall.Handle, reserved uint32, bytesLow uint32, bytesHigh uint32, overlapped *syscall.Overlapped) (err error) {
+	r1, _, e1 := syscall.Syscall6(procUnlockFileEx.Addr(), 5, uintptr(file), uintptr(reserved), uintptr(bytesLow), uintptr(bytesHigh), uintptr(unsafe.Pointer(overlapped)), 0)
+	if r1 == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func VirtualQuery(address uintptr, buffer *MemoryBasicInformation, length uintptr) (err error) {
+	r1, _, e1 := syscall.Syscall(procVirtualQuery.Addr(), 3, uintptr(address), uintptr(unsafe.Pointer(buffer)), uintptr(length))
+	if r1 == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func NetShareAdd(serverName *uint16, level uint32, buf *byte, parmErr *uint16) (neterr error) {
+	r0, _, _ := syscall.Syscall6(procNetShareAdd.Addr(), 4, uintptr(unsafe.Pointer(serverName)), uintptr(level), uintptr(unsafe.Pointer(buf)), uintptr(unsafe.Pointer(parmErr)), 0, 0)
+	if r0 != 0 {
+		neterr = syscall.Errno(r0)
+	}
+	return
+}
+
+func NetShareDel(serverName *uint16, netName *uint16, reserved uint32) (neterr error) {
+	r0, _, _ := syscall.Syscall(procNetShareDel.Addr(), 3, uintptr(unsafe.Pointer(serverName)), uintptr(unsafe.Pointer(netName)), uintptr(reserved))
+	if r0 != 0 {
+		neterr = syscall.Errno(r0)
+	}
+	return
+}
+
+func NetUserGetLocalGroups(serverName *uint16, userName *uint16, level uint32, flags uint32, buf **byte, prefMaxLen uint32, entriesRead *uint32, totalEntries *uint32) (neterr error) {
+	r0, _, _ := syscall.Syscall9(procNetUserGetLocalGroups.Addr(), 8, uintptr(unsafe.Pointer(serverName)), uintptr(unsafe.Pointer(userName)), uintptr(level), uintptr(flags), uintptr(unsafe.Pointer(buf)), uintptr(prefMaxLen), uintptr(unsafe.Pointer(entriesRead)), uintptr(unsafe.Pointer(totalEntries)), 0)
+	if r0 != 0 {
+		neterr = syscall.Errno(r0)
+	}
+	return
+}
+
+func GetProcessMemoryInfo(handle syscall.Handle, memCounters *PROCESS_MEMORY_COUNTERS, cb uint32) (err error) {
+	r1, _, e1 := syscall.Syscall(procGetProcessMemoryInfo.Addr(), 3, uintptr(handle), uintptr(unsafe.Pointer(memCounters)), uintptr(cb))
+	if r1 == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func CreateEnvironmentBlock(block **uint16, token syscall.Token, inheritExisting bool) (err error) {
+	var _p0 uint32
+	if inheritExisting {
+		_p0 = 1
+	}
+	r1, _, e1 := syscall.Syscall(procCreateEnvironmentBlock.Addr(), 3, uintptr(unsafe.Pointer(block)), uintptr(token), uintptr(_p0))
+	if r1 == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func DestroyEnvironmentBlock(block *uint16) (err error) {
+	r1, _, e1 := syscall.Syscall(procDestroyEnvironmentBlock.Addr(), 1, uintptr(unsafe.Pointer(block)), 0, 0)
+	if r1 == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func GetProfilesDirectory(dir *uint16, dirLen *uint32) (err error) {
+	r1, _, e1 := syscall.Syscall(procGetProfilesDirectoryW.Addr(), 2, uintptr(unsafe.Pointer(dir)), uintptr(unsafe.Pointer(dirLen)), 0)
+	if r1 == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+func WSASocket(af int32, typ int32, protocol int32, protinfo *syscall.WSAProtocolInfo, group uint32, flags uint32) (handle syscall.Handle, err error) {
+	r0, _, e1 := syscall.Syscall6(procWSASocketW.Addr(), 6, uintptr(af), uintptr(typ), uintptr(protocol), uintptr(unsafe.Pointer(protinfo)), uintptr(group), uintptr(flags))
+	handle = syscall.Handle(r0)
+	if handle == syscall.InvalidHandle {
+		err = errnoErr(e1)
+	}
+	return
+}
diff --git a/contrib/go/_std_1.20/src/internal/sysinfo/sysinfo.go b/contrib/go/_std_1.20/src/internal/sysinfo/sysinfo.go
new file mode 100644
index 0000000000..961be7abae
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/sysinfo/sysinfo.go
@@ -0,0 +1,31 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package sysinfo implements high level hardware information gathering
+// that can be used for debugging or information purposes.
+package sysinfo
+
+import (
+	internalcpu "internal/cpu"
+	"sync"
+)
+
+type cpuInfo struct {
+	once sync.Once
+	name string
+}
+
+var CPU cpuInfo
+
+func (cpu *cpuInfo) Name() string {
+	cpu.once.Do(func() {
+		// Try to get the information from internal/cpu.
+		if name := internalcpu.Name(); name != "" {
+			cpu.name = name
+			return
+		}
+		// TODO(martisch): use /proc/cpuinfo and /sys/devices/system/cpu/ on Linux as fallback.
+	})
+	return cpu.name
+}
diff --git a/contrib/go/_std_1.20/src/internal/sysinfo/ya.make b/contrib/go/_std_1.20/src/internal/sysinfo/ya.make
new file mode 100644
index 0000000000..734edbe953
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/sysinfo/ya.make
@@ -0,0 +1,7 @@
+GO_LIBRARY()
+
+SRCS(
+    sysinfo.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/testlog/exit.go b/contrib/go/_std_1.20/src/internal/testlog/exit.go
new file mode 100644
index 0000000000..e15defdb5b
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/testlog/exit.go
@@ -0,0 +1,33 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package testlog
+
+import "sync"
+
+// PanicOnExit0 reports whether to panic on a call to os.Exit(0).
+// This is in the testlog package because, like other definitions in
+// package testlog, it is a hook between the testing package and the
+// os package. This is used to ensure that an early call to os.Exit(0)
+// does not cause a test to pass.
+func PanicOnExit0() bool {
+	panicOnExit0.mu.Lock()
+	defer panicOnExit0.mu.Unlock()
+	return panicOnExit0.val
+}
+
+// panicOnExit0 is the flag used for PanicOnExit0. This uses a lock
+// because the value can be cleared via a timer call that may race
+// with calls to os.Exit
+var panicOnExit0 struct {
+	mu  sync.Mutex
+	val bool
+}
+
+// SetPanicOnExit0 sets panicOnExit0 to v.
+func SetPanicOnExit0(v bool) {
+	panicOnExit0.mu.Lock()
+	defer panicOnExit0.mu.Unlock()
+	panicOnExit0.val = v
+}
diff --git a/contrib/go/_std_1.20/src/internal/testlog/log.go b/contrib/go/_std_1.20/src/internal/testlog/log.go
new file mode 100644
index 0000000000..3c5f780ac4
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/testlog/log.go
@@ -0,0 +1,69 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package testlog provides a back-channel communication path
+// between tests and package os, so that cmd/go can see which
+// environment variables and files a test consults.
+package testlog
+
+import "sync/atomic"
+
+// Interface is the interface required of test loggers.
+// The os package will invoke the interface's methods to indicate that
+// it is inspecting the given environment variables or files.
+// Multiple goroutines may call these methods simultaneously.
+type Interface interface {
+	Getenv(key string)
+	Stat(file string)
+	Open(file string)
+	Chdir(dir string)
+}
+
+// logger is the current logger Interface.
+// We use an atomic.Value in case test startup
+// is racing with goroutines started during init.
+// That must not cause a race detector failure,
+// although it will still result in limited visibility
+// into exactly what those goroutines do.
+var logger atomic.Value
+
+// SetLogger sets the test logger implementation for the current process.
+// It must be called only once, at process startup.
+func SetLogger(impl Interface) {
+	if logger.Load() != nil {
+		panic("testlog: SetLogger must be called only once")
+	}
+	logger.Store(&impl)
+}
+
+// Logger returns the current test logger implementation.
+// It returns nil if there is no logger.
+func Logger() Interface {
+	impl := logger.Load()
+	if impl == nil {
+		return nil
+	}
+	return *impl.(*Interface)
+}
+
+// Getenv calls Logger().Getenv, if a logger has been set.
+func Getenv(name string) {
+	if log := Logger(); log != nil {
+		log.Getenv(name)
+	}
+}
+
+// Open calls Logger().Open, if a logger has been set.
+func Open(name string) {
+	if log := Logger(); log != nil {
+		log.Open(name)
+	}
+}
+
+// Stat calls Logger().Stat, if a logger has been set.
+func Stat(name string) {
+	if log := Logger(); log != nil {
+		log.Stat(name)
+	}
+}
diff --git a/contrib/go/_std_1.20/src/internal/testlog/ya.make b/contrib/go/_std_1.20/src/internal/testlog/ya.make
new file mode 100644
index 0000000000..b135ad33f0
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/testlog/ya.make
@@ -0,0 +1,8 @@
+GO_LIBRARY()
+
+SRCS(
+    exit.go
+    log.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/types/errors/codes.go b/contrib/go/_std_1.20/src/internal/types/errors/codes.go
new file mode 100644
index 0000000000..acddcbb9c5
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/types/errors/codes.go
@@ -0,0 +1,1442 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package errors
+
+type Code int
+
+// This file defines the error codes that can be produced during type-checking.
+// Collectively, these codes provide an identifier that may be used to
+// implement special handling for certain types of errors.
+//
+// Error code values should not be changed: add new codes at the end.
+//
+// Error codes should be fine-grained enough that the exact nature of the error
+// can be easily determined, but coarse enough that they are not an
+// implementation detail of the type checking algorithm. As a rule-of-thumb,
+// errors should be considered equivalent if there is a theoretical refactoring
+// of the type checker in which they are emitted in exactly one place. For
+// example, the type checker emits different error messages for "too many
+// arguments" and "too few arguments", but one can imagine an alternative type
+// checker where this check instead just emits a single "wrong number of
+// arguments", so these errors should have the same code.
+//
+// Error code names should be as brief as possible while retaining accuracy and
+// distinctiveness. In most cases names should start with an adjective
+// describing the nature of the error (e.g. "invalid", "unused", "misplaced"),
+// and end with a noun identifying the relevant language object. For example,
+// "_DuplicateDecl" or "_InvalidSliceExpr". For brevity, naming follows the
+// convention that "bad" implies a problem with syntax, and "invalid" implies a
+// problem with types.
+
+const (
+	// InvalidSyntaxTree occurs if an invalid syntax tree is provided
+	// to the type checker. It should never happen.
+	InvalidSyntaxTree Code = -1
+)
+
+const (
+	// The zero Code value indicates an unset (invalid) error code.
+	_ Code = iota
+
+	// Test is reserved for errors that only apply while in self-test mode.
+	Test
+
+	// BlankPkgName occurs when a package name is the blank identifier "_".
+	//
+	// Per the spec:
+	//  "The PackageName must not be the blank identifier."
+	//
+	// Example:
+	//  package _
+	BlankPkgName
+
+	// MismatchedPkgName occurs when a file's package name doesn't match the
+	// package name already established by other files.
+	MismatchedPkgName
+
+	// InvalidPkgUse occurs when a package identifier is used outside of a
+	// selector expression.
+	//
+	// Example:
+	//  import "fmt"
+	//
+	//  var _ = fmt
+	InvalidPkgUse
+
+	// BadImportPath occurs when an import path is not valid.
+	BadImportPath
+
+	// BrokenImport occurs when importing a package fails.
+	//
+	// Example:
+	//  import "amissingpackage"
+	BrokenImport
+
+	// ImportCRenamed occurs when the special import "C" is renamed. "C" is a
+	// pseudo-package, and must not be renamed.
+	//
+	// Example:
+	//  import _ "C"
+	ImportCRenamed
+
+	// UnusedImport occurs when an import is unused.
+	//
+	// Example:
+	//  import "fmt"
+	//
+	//  func main() {}
+	UnusedImport
+
+	// InvalidInitCycle occurs when an invalid cycle is detected within the
+	// initialization graph.
+	//
+	// Example:
+	//  var x int = f()
+	//
+	//  func f() int { return x }
+	InvalidInitCycle
+
+	// DuplicateDecl occurs when an identifier is declared multiple times.
+	//
+	// Example:
+	//  var x = 1
+	//  var x = 2
+	DuplicateDecl
+
+	// InvalidDeclCycle occurs when a declaration cycle is not valid.
+	//
+	// Example:
+	//  type S struct {
+	//  	S
+	//  }
+	//
+	InvalidDeclCycle
+
+	// InvalidTypeCycle occurs when a cycle in type definitions results in a
+	// type that is not well-defined.
+	//
+	// Example:
+	//  import "unsafe"
+	//
+	//  type T [unsafe.Sizeof(T{})]int
+	InvalidTypeCycle
+
+	// InvalidConstInit occurs when a const declaration has a non-constant
+	// initializer.
+	//
+	// Example:
+	//  var x int
+	//  const _ = x
+	InvalidConstInit
+
+	// InvalidConstVal occurs when a const value cannot be converted to its
+	// target type.
+	//
+	// TODO(findleyr): this error code and example are not very clear. Consider
+	// removing it.
+	//
+	// Example:
+	//  const _ = 1 << "hello"
+	InvalidConstVal
+
+	// InvalidConstType occurs when the underlying type in a const declaration
+	// is not a valid constant type.
+	//
+	// Example:
+	//  const c *int = 4
+	InvalidConstType
+
+	// UntypedNilUse occurs when the predeclared (untyped) value nil is used to
+	// initialize a variable declared without an explicit type.
+	//
+	// Example:
+	//  var x = nil
+	UntypedNilUse
+
+	// WrongAssignCount occurs when the number of values on the right-hand side
+	// of an assignment or initialization expression does not match the number
+	// of variables on the left-hand side.
+	//
+	// Example:
+	//  var x = 1, 2
+	WrongAssignCount
+
+	// UnassignableOperand occurs when the left-hand side of an assignment is
+	// not assignable.
+	//
+	// Example:
+	//  func f() {
+	//  	const c = 1
+	//  	c = 2
+	//  }
+	UnassignableOperand
+
+	// NoNewVar occurs when a short variable declaration (':=') does not declare
+	// new variables.
+	//
+	// Example:
+	//  func f() {
+	//  	x := 1
+	//  	x := 2
+	//  }
+	NoNewVar
+
+	// MultiValAssignOp occurs when an assignment operation (+=, *=, etc) does
+	// not have single-valued left-hand or right-hand side.
+	//
+	// Per the spec:
+	//  "In assignment operations, both the left- and right-hand expression lists
+	//  must contain exactly one single-valued expression"
+	//
+	// Example:
+	//  func f() int {
+	//  	x, y := 1, 2
+	//  	x, y += 1
+	//  	return x + y
+	//  }
+	MultiValAssignOp
+
+	// InvalidIfaceAssign occurs when a value of type T is used as an
+	// interface, but T does not implement a method of the expected interface.
+	//
+	// Example:
+	//  type I interface {
+	//  	f()
+	//  }
+	//
+	//  type T int
+	//
+	//  var x I = T(1)
+	InvalidIfaceAssign
+
+	// InvalidChanAssign occurs when a chan assignment is invalid.
+	//
+	// Per the spec, a value x is assignable to a channel type T if:
+	//  "x is a bidirectional channel value, T is a channel type, x's type V and
+	//  T have identical element types, and at least one of V or T is not a
+	//  defined type."
+	//
+	// Example:
+	//  type T1 chan int
+	//  type T2 chan int
+	//
+	//  var x T1
+	//  // Invalid assignment because both types are named
+	//  var _ T2 = x
+	InvalidChanAssign
+
+	// IncompatibleAssign occurs when the type of the right-hand side expression
+	// in an assignment cannot be assigned to the type of the variable being
+	// assigned.
+	//
+	// Example:
+	//  var x []int
+	//  var _ int = x
+	IncompatibleAssign
+
+	// UnaddressableFieldAssign occurs when trying to assign to a struct field
+	// in a map value.
+	//
+	// Example:
+	//  func f() {
+	//  	m := make(map[string]struct{i int})
+	//  	m["foo"].i = 42
+	//  }
+	UnaddressableFieldAssign
+
+	// NotAType occurs when the identifier used as the underlying type in a type
+	// declaration or the right-hand side of a type alias does not denote a type.
+	//
+	// Example:
+	//  var S = 2
+	//
+	//  type T S
+	NotAType
+
+	// InvalidArrayLen occurs when an array length is not a constant value.
+	//
+	// Example:
+	//  var n = 3
+	//  var _ = [n]int{}
+	InvalidArrayLen
+
+	// BlankIfaceMethod occurs when a method name is '_'.
+	//
+	// Per the spec:
+	//  "The name of each explicitly specified method must be unique and not
+	//  blank."
+	//
+	// Example:
+	//  type T interface {
+	//  	_(int)
+	//  }
+	BlankIfaceMethod
+
+	// IncomparableMapKey occurs when a map key type does not support the == and
+	// != operators.
+	//
+	// Per the spec:
+	//  "The comparison operators == and != must be fully defined for operands of
+	//  the key type; thus the key type must not be a function, map, or slice."
+	//
+	// Example:
+	//  var x map[T]int
+	//
+	//  type T []int
+	IncomparableMapKey
+
+	// InvalidIfaceEmbed occurs when a non-interface type is embedded in an
+	// interface (for go 1.17 or earlier).
+	_ // not used anymore
+
+	// InvalidPtrEmbed occurs when an embedded field is of the pointer form *T,
+	// and T itself is itself a pointer, an unsafe.Pointer, or an interface.
+	//
+	// Per the spec:
+	//  "An embedded field must be specified as a type name T or as a pointer to
+	//  a non-interface type name *T, and T itself may not be a pointer type."
+	//
+	// Example:
+	//  type T *int
+	//
+	//  type S struct {
+	//  	*T
+	//  }
+	InvalidPtrEmbed
+
+	// BadRecv occurs when a method declaration does not have exactly one
+	// receiver parameter.
+	//
+	// Example:
+	//  func () _() {}
+	BadRecv
+
+	// InvalidRecv occurs when a receiver type expression is not of the form T
+	// or *T, or T is a pointer type.
+	//
+	// Example:
+	//  type T struct {}
+	//
+	//  func (**T) m() {}
+	InvalidRecv
+
+	// DuplicateFieldAndMethod occurs when an identifier appears as both a field
+	// and method name.
+	//
+	// Example:
+	//  type T struct {
+	//  	m int
+	//  }
+	//
+	//  func (T) m() {}
+	DuplicateFieldAndMethod
+
+	// DuplicateMethod occurs when two methods on the same receiver type have
+	// the same name.
+	//
+	// Example:
+	//  type T struct {}
+	//  func (T) m() {}
+	//  func (T) m(i int) int { return i }
+	DuplicateMethod
+
+	// InvalidBlank occurs when a blank identifier is used as a value or type.
+	//
+	// Per the spec:
+	//  "The blank identifier may appear as an operand only on the left-hand side
+	//  of an assignment."
+	//
+	// Example:
+	//  var x = _
+	InvalidBlank
+
+	// InvalidIota occurs when the predeclared identifier iota is used outside
+	// of a constant declaration.
+	//
+	// Example:
+	//  var x = iota
+	InvalidIota
+
+	// MissingInitBody occurs when an init function is missing its body.
+	//
+	// Example:
+	//  func init()
+	MissingInitBody
+
+	// InvalidInitSig occurs when an init function declares parameters or
+	// results.
+	//
+	// Deprecated: no longer emitted by the type checker. _InvalidInitDecl is
+	// used instead.
+	InvalidInitSig
+
+	// InvalidInitDecl occurs when init is declared as anything other than a
+	// function.
+	//
+	// Example:
+	//  var init = 1
+	//
+	// Example:
+	//  func init() int { return 1 }
+	InvalidInitDecl
+
+	// InvalidMainDecl occurs when main is declared as anything other than a
+	// function, in a main package.
+	InvalidMainDecl
+
+	// TooManyValues occurs when a function returns too many values for the
+	// expression context in which it is used.
+	//
+	// Example:
+	//  func ReturnTwo() (int, int) {
+	//  	return 1, 2
+	//  }
+	//
+	//  var x = ReturnTwo()
+	TooManyValues
+
+	// NotAnExpr occurs when a type expression is used where a value expression
+	// is expected.
+	//
+	// Example:
+	//  type T struct {}
+	//
+	//  func f() {
+	//  	T
+	//  }
+	NotAnExpr
+
+	// TruncatedFloat occurs when a float constant is truncated to an integer
+	// value.
+	//
+	// Example:
+	//  var _ int = 98.6
+	TruncatedFloat
+
+	// NumericOverflow occurs when a numeric constant overflows its target type.
+	//
+	// Example:
+	//  var x int8 = 1000
+	NumericOverflow
+
+	// UndefinedOp occurs when an operator is not defined for the type(s) used
+	// in an operation.
+	//
+	// Example:
+	//  var c = "a" - "b"
+	UndefinedOp
+
+	// MismatchedTypes occurs when operand types are incompatible in a binary
+	// operation.
+	//
+	// Example:
+	//  var a = "hello"
+	//  var b = 1
+	//  var c = a - b
+	MismatchedTypes
+
+	// DivByZero occurs when a division operation is provable at compile
+	// time to be a division by zero.
+	//
+	// Example:
+	//  const divisor = 0
+	//  var x int = 1/divisor
+	DivByZero
+
+	// NonNumericIncDec occurs when an increment or decrement operator is
+	// applied to a non-numeric value.
+	//
+	// Example:
+	//  func f() {
+	//  	var c = "c"
+	//  	c++
+	//  }
+	NonNumericIncDec
+
+	// UnaddressableOperand occurs when the & operator is applied to an
+	// unaddressable expression.
+	//
+	// Example:
+	//  var x = &1
+	UnaddressableOperand
+
+	// InvalidIndirection occurs when a non-pointer value is indirected via the
+	// '*' operator.
+	//
+	// Example:
+	//  var x int
+	//  var y = *x
+	InvalidIndirection
+
+	// NonIndexableOperand occurs when an index operation is applied to a value
+	// that cannot be indexed.
+	//
+	// Example:
+	//  var x = 1
+	//  var y = x[1]
+	NonIndexableOperand
+
+	// InvalidIndex occurs when an index argument is not of integer type,
+	// negative, or out-of-bounds.
+	//
+	// Example:
+	//  var s = [...]int{1,2,3}
+	//  var x = s[5]
+	//
+	// Example:
+	//  var s = []int{1,2,3}
+	//  var _ = s[-1]
+	//
+	// Example:
+	//  var s = []int{1,2,3}
+	//  var i string
+	//  var _ = s[i]
+	InvalidIndex
+
+	// SwappedSliceIndices occurs when constant indices in a slice expression
+	// are decreasing in value.
+	//
+	// Example:
+	//  var _ = []int{1,2,3}[2:1]
+	SwappedSliceIndices
+
+	// NonSliceableOperand occurs when a slice operation is applied to a value
+	// whose type is not sliceable, or is unaddressable.
+	//
+	// Example:
+	//  var x = [...]int{1, 2, 3}[:1]
+	//
+	// Example:
+	//  var x = 1
+	//  var y = 1[:1]
+	NonSliceableOperand
+
+	// InvalidSliceExpr occurs when a three-index slice expression (a[x:y:z]) is
+	// applied to a string.
+	//
+	// Example:
+	//  var s = "hello"
+	//  var x = s[1:2:3]
+	InvalidSliceExpr
+
+	// InvalidShiftCount occurs when the right-hand side of a shift operation is
+	// either non-integer, negative, or too large.
+	//
+	// Example:
+	//  var (
+	//  	x string
+	//  	y int = 1 << x
+	//  )
+	InvalidShiftCount
+
+	// InvalidShiftOperand occurs when the shifted operand is not an integer.
+	//
+	// Example:
+	//  var s = "hello"
+	//  var x = s << 2
+	InvalidShiftOperand
+
+	// InvalidReceive occurs when there is a channel receive from a value that
+	// is either not a channel, or is a send-only channel.
+	//
+	// Example:
+	//  func f() {
+	//  	var x = 1
+	//  	<-x
+	//  }
+	InvalidReceive
+
+	// InvalidSend occurs when there is a channel send to a value that is not a
+	// channel, or is a receive-only channel.
+	//
+	// Example:
+	//  func f() {
+	//  	var x = 1
+	//  	x <- "hello!"
+	//  }
+	InvalidSend
+
+	// DuplicateLitKey occurs when an index is duplicated in a slice, array, or
+	// map literal.
+	//
+	// Example:
+	//  var _ = []int{0:1, 0:2}
+	//
+	// Example:
+	//  var _ = map[string]int{"a": 1, "a": 2}
+	DuplicateLitKey
+
+	// MissingLitKey occurs when a map literal is missing a key expression.
+	//
+	// Example:
+	//  var _ = map[string]int{1}
+	MissingLitKey
+
+	// InvalidLitIndex occurs when the key in a key-value element of a slice or
+	// array literal is not an integer constant.
+	//
+	// Example:
+	//  var i = 0
+	//  var x = []string{i: "world"}
+	InvalidLitIndex
+
+	// OversizeArrayLit occurs when an array literal exceeds its length.
+	//
+	// Example:
+	//  var _ = [2]int{1,2,3}
+	OversizeArrayLit
+
+	// MixedStructLit occurs when a struct literal contains a mix of positional
+	// and named elements.
+	//
+	// Example:
+	//  var _ = struct{i, j int}{i: 1, 2}
+	MixedStructLit
+
+	// InvalidStructLit occurs when a positional struct literal has an incorrect
+	// number of values.
+	//
+	// Example:
+	//  var _ = struct{i, j int}{1,2,3}
+	InvalidStructLit
+
+	// MissingLitField occurs when a struct literal refers to a field that does
+	// not exist on the struct type.
+	//
+	// Example:
+	//  var _ = struct{i int}{j: 2}
+	MissingLitField
+
+	// DuplicateLitField occurs when a struct literal contains duplicated
+	// fields.
+	//
+	// Example:
+	//  var _ = struct{i int}{i: 1, i: 2}
+	DuplicateLitField
+
+	// UnexportedLitField occurs when a positional struct literal implicitly
+	// assigns an unexported field of an imported type.
+	UnexportedLitField
+
+	// InvalidLitField occurs when a field name is not a valid identifier.
+	//
+	// Example:
+	//  var _ = struct{i int}{1: 1}
+	InvalidLitField
+
+	// UntypedLit occurs when a composite literal omits a required type
+	// identifier.
+	//
+	// Example:
+	//  type outer struct{
+	//  	inner struct { i int }
+	//  }
+	//
+	//  var _ = outer{inner: {1}}
+	UntypedLit
+
+	// InvalidLit occurs when a composite literal expression does not match its
+	// type.
+	//
+	// Example:
+	//  type P *struct{
+	//  	x int
+	//  }
+	//  var _ = P {}
+	InvalidLit
+
+	// AmbiguousSelector occurs when a selector is ambiguous.
+	//
+	// Example:
+	//  type E1 struct { i int }
+	//  type E2 struct { i int }
+	//  type T struct { E1; E2 }
+	//
+	//  var x T
+	//  var _ = x.i
+	AmbiguousSelector
+
+	// UndeclaredImportedName occurs when a package-qualified identifier is
+	// undeclared by the imported package.
+	//
+	// Example:
+	//  import "go/types"
+	//
+	//  var _ = types.NotAnActualIdentifier
+	UndeclaredImportedName
+
+	// UnexportedName occurs when a selector refers to an unexported identifier
+	// of an imported package.
+	//
+	// Example:
+	//  import "reflect"
+	//
+	//  type _ reflect.flag
+	UnexportedName
+
+	// UndeclaredName occurs when an identifier is not declared in the current
+	// scope.
+	//
+	// Example:
+	//  var x T
+	UndeclaredName
+
+	// MissingFieldOrMethod occurs when a selector references a field or method
+	// that does not exist.
+	//
+	// Example:
+	//  type T struct {}
+	//
+	//  var x = T{}.f
+	MissingFieldOrMethod
+
+	// BadDotDotDotSyntax occurs when a "..." occurs in a context where it is
+	// not valid.
+	//
+	// Example:
+	//  var _ = map[int][...]int{0: {}}
+	BadDotDotDotSyntax
+
+	// NonVariadicDotDotDot occurs when a "..." is used on the final argument to
+	// a non-variadic function.
+	//
+	// Example:
+	//  func printArgs(s []string) {
+	//  	for _, a := range s {
+	//  		println(a)
+	//  	}
+	//  }
+	//
+	//  func f() {
+	//  	s := []string{"a", "b", "c"}
+	//  	printArgs(s...)
+	//  }
+	NonVariadicDotDotDot
+
+	// MisplacedDotDotDot occurs when a "..." is used somewhere other than the
+	// final argument in a function declaration.
+	//
+	// Example:
+	// 	func f(...int, int)
+	MisplacedDotDotDot
+
+	_ // InvalidDotDotDotOperand was removed.
+
+	// InvalidDotDotDot occurs when a "..." is used in a non-variadic built-in
+	// function.
+	//
+	// Example:
+	//  var s = []int{1, 2, 3}
+	//  var l = len(s...)
+	InvalidDotDotDot
+
+	// UncalledBuiltin occurs when a built-in function is used as a
+	// function-valued expression, instead of being called.
+	//
+	// Per the spec:
+	//  "The built-in functions do not have standard Go types, so they can only
+	//  appear in call expressions; they cannot be used as function values."
+	//
+	// Example:
+	//  var _ = copy
+	UncalledBuiltin
+
+	// InvalidAppend occurs when append is called with a first argument that is
+	// not a slice.
+	//
+	// Example:
+	//  var _ = append(1, 2)
+	InvalidAppend
+
+	// InvalidCap occurs when an argument to the cap built-in function is not of
+	// supported type.
+	//
+	// See https://golang.org/ref/spec#Length_and_capacity for information on
+	// which underlying types are supported as arguments to cap and len.
+	//
+	// Example:
+	//  var s = 2
+	//  var x = cap(s)
+	InvalidCap
+
+	// InvalidClose occurs when close(...) is called with an argument that is
+	// not of channel type, or that is a receive-only channel.
+	//
+	// Example:
+	//  func f() {
+	//  	var x int
+	//  	close(x)
+	//  }
+	InvalidClose
+
+	// InvalidCopy occurs when the arguments are not of slice type or do not
+	// have compatible type.
+	//
+	// See https://golang.org/ref/spec#Appending_and_copying_slices for more
+	// information on the type requirements for the copy built-in.
+	//
+	// Example:
+	//  func f() {
+	//  	var x []int
+	//  	y := []int64{1,2,3}
+	//  	copy(x, y)
+	//  }
+	InvalidCopy
+
+	// InvalidComplex occurs when the complex built-in function is called with
+	// arguments with incompatible types.
+	//
+	// Example:
+	//  var _ = complex(float32(1), float64(2))
+	InvalidComplex
+
+	// InvalidDelete occurs when the delete built-in function is called with a
+	// first argument that is not a map.
+	//
+	// Example:
+	//  func f() {
+	//  	m := "hello"
+	//  	delete(m, "e")
+	//  }
+	InvalidDelete
+
+	// InvalidImag occurs when the imag built-in function is called with an
+	// argument that does not have complex type.
+	//
+	// Example:
+	//  var _ = imag(int(1))
+	InvalidImag
+
+	// InvalidLen occurs when an argument to the len built-in function is not of
+	// supported type.
+	//
+	// See https://golang.org/ref/spec#Length_and_capacity for information on
+	// which underlying types are supported as arguments to cap and len.
+	//
+	// Example:
+	//  var s = 2
+	//  var x = len(s)
+	InvalidLen
+
+	// SwappedMakeArgs occurs when make is called with three arguments, and its
+	// length argument is larger than its capacity argument.
+	//
+	// Example:
+	//  var x = make([]int, 3, 2)
+	SwappedMakeArgs
+
+	// InvalidMake occurs when make is called with an unsupported type argument.
+	//
+	// See https://golang.org/ref/spec#Making_slices_maps_and_channels for
+	// information on the types that may be created using make.
+	//
+	// Example:
+	//  var x = make(int)
+	InvalidMake
+
+	// InvalidReal occurs when the real built-in function is called with an
+	// argument that does not have complex type.
+	//
+	// Example:
+	//  var _ = real(int(1))
+	InvalidReal
+
+	// InvalidAssert occurs when a type assertion is applied to a
+	// value that is not of interface type.
+	//
+	// Example:
+	//  var x = 1
+	//  var _ = x.(float64)
+	InvalidAssert
+
+	// ImpossibleAssert occurs for a type assertion x.(T) when the value x of
+	// interface cannot have dynamic type T, due to a missing or mismatching
+	// method on T.
+	//
+	// Example:
+	//  type T int
+	//
+	//  func (t *T) m() int { return int(*t) }
+	//
+	//  type I interface { m() int }
+	//
+	//  var x I
+	//  var _ = x.(T)
+	ImpossibleAssert
+
+	// InvalidConversion occurs when the argument type cannot be converted to the
+	// target.
+	//
+	// See https://golang.org/ref/spec#Conversions for the rules of
+	// convertibility.
+	//
+	// Example:
+	//  var x float64
+	//  var _ = string(x)
+	InvalidConversion
+
+	// InvalidUntypedConversion occurs when there is no valid implicit
+	// conversion from an untyped value satisfying the type constraints of the
+	// context in which it is used.
+	//
+	// Example:
+	//  var _ = 1 + []int{}
+	InvalidUntypedConversion
+
+	// BadOffsetofSyntax occurs when unsafe.Offsetof is called with an argument
+	// that is not a selector expression.
+	//
+	// Example:
+	//  import "unsafe"
+	//
+	//  var x int
+	//  var _ = unsafe.Offsetof(x)
+	BadOffsetofSyntax
+
+	// InvalidOffsetof occurs when unsafe.Offsetof is called with a method
+	// selector, rather than a field selector, or when the field is embedded via
+	// a pointer.
+	//
+	// Per the spec:
+	//
+	//  "If f is an embedded field, it must be reachable without pointer
+	//  indirections through fields of the struct. "
+	//
+	// Example:
+	//  import "unsafe"
+	//
+	//  type T struct { f int }
+	//  type S struct { *T }
+	//  var s S
+	//  var _ = unsafe.Offsetof(s.f)
+	//
+	// Example:
+	//  import "unsafe"
+	//
+	//  type S struct{}
+	//
+	//  func (S) m() {}
+	//
+	//  var s S
+	//  var _ = unsafe.Offsetof(s.m)
+	InvalidOffsetof
+
+	// UnusedExpr occurs when a side-effect free expression is used as a
+	// statement. Such a statement has no effect.
+	//
+	// Example:
+	//  func f(i int) {
+	//  	i*i
+	//  }
+	UnusedExpr
+
+	// UnusedVar occurs when a variable is declared but unused.
+	//
+	// Example:
+	//  func f() {
+	//  	x := 1
+	//  }
+	UnusedVar
+
+	// MissingReturn occurs when a function with results is missing a return
+	// statement.
+	//
+	// Example:
+	//  func f() int {}
+	MissingReturn
+
+	// WrongResultCount occurs when a return statement returns an incorrect
+	// number of values.
+	//
+	// Example:
+	//  func ReturnOne() int {
+	//  	return 1, 2
+	//  }
+	WrongResultCount
+
+	// OutOfScopeResult occurs when the name of a value implicitly returned by
+	// an empty return statement is shadowed in a nested scope.
+	//
+	// Example:
+	//  func factor(n int) (i int) {
+	//  	for i := 2; i < n; i++ {
+	//  		if n%i == 0 {
+	//  			return
+	//  		}
+	//  	}
+	//  	return 0
+	//  }
+	OutOfScopeResult
+
+	// InvalidCond occurs when an if condition is not a boolean expression.
+	//
+	// Example:
+	//  func checkReturn(i int) {
+	//  	if i {
+	//  		panic("non-zero return")
+	//  	}
+	//  }
+	InvalidCond
+
+	// InvalidPostDecl occurs when there is a declaration in a for-loop post
+	// statement.
+	//
+	// Example:
+	//  func f() {
+	//  	for i := 0; i < 10; j := 0 {}
+	//  }
+	InvalidPostDecl
+
+	_ // InvalidChanRange was removed.
+
+	// InvalidIterVar occurs when two iteration variables are used while ranging
+	// over a channel.
+	//
+	// Example:
+	//  func f(c chan int) {
+	//  	for k, v := range c {
+	//  		println(k, v)
+	//  	}
+	//  }
+	InvalidIterVar
+
+	// InvalidRangeExpr occurs when the type of a range expression is not array,
+	// slice, string, map, or channel.
+	//
+	// Example:
+	//  func f(i int) {
+	//  	for j := range i {
+	//  		println(j)
+	//  	}
+	//  }
+	InvalidRangeExpr
+
+	// MisplacedBreak occurs when a break statement is not within a for, switch,
+	// or select statement of the innermost function definition.
+	//
+	// Example:
+	//  func f() {
+	//  	break
+	//  }
+	MisplacedBreak
+
+	// MisplacedContinue occurs when a continue statement is not within a for
+	// loop of the innermost function definition.
+	//
+	// Example:
+	//  func sumeven(n int) int {
+	//  	proceed := func() {
+	//  		continue
+	//  	}
+	//  	sum := 0
+	//  	for i := 1; i <= n; i++ {
+	//  		if i % 2 != 0 {
+	//  			proceed()
+	//  		}
+	//  		sum += i
+	//  	}
+	//  	return sum
+	//  }
+	MisplacedContinue
+
+	// MisplacedFallthrough occurs when a fallthrough statement is not within an
+	// expression switch.
+	//
+	// Example:
+	//  func typename(i interface{}) string {
+	//  	switch i.(type) {
+	//  	case int64:
+	//  		fallthrough
+	//  	case int:
+	//  		return "int"
+	//  	}
+	//  	return "unsupported"
+	//  }
+	MisplacedFallthrough
+
+	// DuplicateCase occurs when a type or expression switch has duplicate
+	// cases.
+	//
+	// Example:
+	//  func printInt(i int) {
+	//  	switch i {
+	//  	case 1:
+	//  		println("one")
+	//  	case 1:
+	//  		println("One")
+	//  	}
+	//  }
+	DuplicateCase
+
+	// DuplicateDefault occurs when a type or expression switch has multiple
+	// default clauses.
+	//
+	// Example:
+	//  func printInt(i int) {
+	//  	switch i {
+	//  	case 1:
+	//  		println("one")
+	//  	default:
+	//  		println("One")
+	//  	default:
+	//  		println("1")
+	//  	}
+	//  }
+	DuplicateDefault
+
+	// BadTypeKeyword occurs when a .(type) expression is used anywhere other
+	// than a type switch.
+	//
+	// Example:
+	//  type I interface {
+	//  	m()
+	//  }
+	//  var t I
+	//  var _ = t.(type)
+	BadTypeKeyword
+
+	// InvalidTypeSwitch occurs when .(type) is used on an expression that is
+	// not of interface type.
+	//
+	// Example:
+	//  func f(i int) {
+	//  	switch x := i.(type) {}
+	//  }
+	InvalidTypeSwitch
+
+	// InvalidExprSwitch occurs when a switch expression is not comparable.
+	//
+	// Example:
+	//  func _() {
+	//  	var a struct{ _ func() }
+	//  	switch a /* ERROR cannot switch on a */ {
+	//  	}
+	//  }
+	InvalidExprSwitch
+
+	// InvalidSelectCase occurs when a select case is not a channel send or
+	// receive.
+	//
+	// Example:
+	//  func checkChan(c <-chan int) bool {
+	//  	select {
+	//  	case c:
+	//  		return true
+	//  	default:
+	//  		return false
+	//  	}
+	//  }
+	InvalidSelectCase
+
+	// UndeclaredLabel occurs when an undeclared label is jumped to.
+	//
+	// Example:
+	//  func f() {
+	//  	goto L
+	//  }
+	UndeclaredLabel
+
+	// DuplicateLabel occurs when a label is declared more than once.
+	//
+	// Example:
+	//  func f() int {
+	//  L:
+	//  L:
+	//  	return 1
+	//  }
+	DuplicateLabel
+
+	// MisplacedLabel occurs when a break or continue label is not on a for,
+	// switch, or select statement.
+	//
+	// Example:
+	//  func f() {
+	//  L:
+	//  	a := []int{1,2,3}
+	//  	for _, e := range a {
+	//  		if e > 10 {
+	//  			break L
+	//  		}
+	//  		println(a)
+	//  	}
+	//  }
+	MisplacedLabel
+
+	// UnusedLabel occurs when a label is declared and not used.
+	//
+	// Example:
+	//  func f() {
+	//  L:
+	//  }
+	UnusedLabel
+
+	// JumpOverDecl occurs when a label jumps over a variable declaration.
+	//
+	// Example:
+	//  func f() int {
+	//  	goto L
+	//  	x := 2
+	//  L:
+	//  	x++
+	//  	return x
+	//  }
+	JumpOverDecl
+
+	// JumpIntoBlock occurs when a forward jump goes to a label inside a nested
+	// block.
+	//
+	// Example:
+	//  func f(x int) {
+	//  	goto L
+	//  	if x > 0 {
+	//  	L:
+	//  		print("inside block")
+	//  	}
+	// }
+	JumpIntoBlock
+
+	// InvalidMethodExpr occurs when a pointer method is called but the argument
+	// is not addressable.
+	//
+	// Example:
+	//  type T struct {}
+	//
+	//  func (*T) m() int { return 1 }
+	//
+	//  var _ = T.m(T{})
+	InvalidMethodExpr
+
+	// WrongArgCount occurs when too few or too many arguments are passed by a
+	// function call.
+	//
+	// Example:
+	//  func f(i int) {}
+	//  var x = f()
+	WrongArgCount
+
+	// InvalidCall occurs when an expression is called that is not of function
+	// type.
+	//
+	// Example:
+	//  var x = "x"
+	//  var y = x()
+	InvalidCall
+
+	// UnusedResults occurs when a restricted expression-only built-in function
+	// is suspended via go or defer. Such a suspension discards the results of
+	// these side-effect free built-in functions, and therefore is ineffectual.
+	//
+	// Example:
+	//  func f(a []int) int {
+	//  	defer len(a)
+	//  	return i
+	//  }
+	UnusedResults
+
+	// InvalidDefer occurs when a deferred expression is not a function call,
+	// for example if the expression is a type conversion.
+	//
+	// Example:
+	//  func f(i int) int {
+	//  	defer int32(i)
+	//  	return i
+	//  }
+	InvalidDefer
+
+	// InvalidGo occurs when a go expression is not a function call, for example
+	// if the expression is a type conversion.
+	//
+	// Example:
+	//  func f(i int) int {
+	//  	go int32(i)
+	//  	return i
+	//  }
+	InvalidGo
+
+	// All codes below were added in Go 1.17.
+
+	// BadDecl occurs when a declaration has invalid syntax.
+	BadDecl
+
+	// RepeatedDecl occurs when an identifier occurs more than once on the left
+	// hand side of a short variable declaration.
+	//
+	// Example:
+	//  func _() {
+	//  	x, y, y := 1, 2, 3
+	//  }
+	RepeatedDecl
+
+	// InvalidUnsafeAdd occurs when unsafe.Add is called with a
+	// length argument that is not of integer type.
+	// It also occurs if it is used in a package compiled for a
+	// language version before go1.17.
+	//
+	// Example:
+	//  import "unsafe"
+	//
+	//  var p unsafe.Pointer
+	//  var _ = unsafe.Add(p, float64(1))
+	InvalidUnsafeAdd
+
+	// InvalidUnsafeSlice occurs when unsafe.Slice is called with a
+	// pointer argument that is not of pointer type or a length argument
+	// that is not of integer type, negative, or out of bounds.
+	// It also occurs if it is used in a package compiled for a language
+	// version before go1.17.
+	//
+	// Example:
+	//  import "unsafe"
+	//
+	//  var x int
+	//  var _ = unsafe.Slice(x, 1)
+	//
+	// Example:
+	//  import "unsafe"
+	//
+	//  var x int
+	//  var _ = unsafe.Slice(&x, float64(1))
+	//
+	// Example:
+	//  import "unsafe"
+	//
+	//  var x int
+	//  var _ = unsafe.Slice(&x, -1)
+	//
+	// Example:
+	//  import "unsafe"
+	//
+	//  var x int
+	//  var _ = unsafe.Slice(&x, uint64(1) << 63)
+	InvalidUnsafeSlice
+
+	// All codes below were added in Go 1.18.
+
+	// UnsupportedFeature occurs when a language feature is used that is not
+	// supported at this Go version.
+	UnsupportedFeature
+
+	// NotAGenericType occurs when a non-generic type is used where a generic
+	// type is expected: in type or function instantiation.
+	//
+	// Example:
+	//  type T int
+	//
+	//  var _ T[int]
+	NotAGenericType
+
+	// WrongTypeArgCount occurs when a type or function is instantiated with an
+	// incorrent number of type arguments, including when a generic type or
+	// function is used without instantiation.
+	//
+	// Errors inolving failed type inference are assigned other error codes.
+	//
+	// Example:
+	//  type T[p any] int
+	//
+	//  var _ T[int, string]
+	//
+	// Example:
+	//  func f[T any]() {}
+	//
+	//  var x = f
+	WrongTypeArgCount
+
+	// CannotInferTypeArgs occurs when type or function type argument inference
+	// fails to infer all type arguments.
+	//
+	// Example:
+	//  func f[T any]() {}
+	//
+	//  func _() {
+	//  	f()
+	//  }
+	CannotInferTypeArgs
+
+	// InvalidTypeArg occurs when a type argument does not satisfy its
+	// corresponding type parameter constraints.
+	//
+	// Example:
+	//  type T[P ~int] struct{}
+	//
+	//  var _ T[string]
+	InvalidTypeArg // arguments? InferenceFailed
+
+	// InvalidInstanceCycle occurs when an invalid cycle is detected
+	// within the instantiation graph.
+	//
+	// Example:
+	//  func f[T any]() { f[*T]() }
+	InvalidInstanceCycle
+
+	// InvalidUnion occurs when an embedded union or approximation element is
+	// not valid.
+	//
+	// Example:
+	//  type _ interface {
+	//   	~int | interface{ m() }
+	//  }
+	InvalidUnion
+
+	// MisplacedConstraintIface occurs when a constraint-type interface is used
+	// outside of constraint position.
+	//
+	// Example:
+	//   type I interface { ~int }
+	//
+	//   var _ I
+	MisplacedConstraintIface
+
+	// InvalidMethodTypeParams occurs when methods have type parameters.
+	//
+	// It cannot be encountered with an AST parsed using go/parser.
+	InvalidMethodTypeParams
+
+	// MisplacedTypeParam occurs when a type parameter is used in a place where
+	// it is not permitted.
+	//
+	// Example:
+	//  type T[P any] P
+	//
+	// Example:
+	//  type T[P any] struct{ *P }
+	MisplacedTypeParam
+
+	// InvalidUnsafeSliceData occurs when unsafe.SliceData is called with
+	// an argument that is not of slice type. It also occurs if it is used
+	// in a package compiled for a language version before go1.20.
+	//
+	// Example:
+	//  import "unsafe"
+	//
+	//  var x int
+	//  var _ = unsafe.SliceData(x)
+	InvalidUnsafeSliceData
+
+	// InvalidUnsafeString occurs when unsafe.String is called with
+	// a length argument that is not of integer type, negative, or
+	// out of bounds. It also occurs if it is used in a package
+	// compiled for a language version before go1.20.
+	//
+	// Example:
+	//  import "unsafe"
+	//
+	//  var b [10]byte
+	//  var _ = unsafe.String(&b[0], -1)
+	InvalidUnsafeString
+
+	// InvalidUnsafeStringData occurs if it is used in a package
+	// compiled for a language version before go1.20.
+	_ // not used anymore
+
+	// InvalidClear occurs when clear is called with an argument
+	// that is not of map, slice, or pointer-to-array type.
+	//
+	// Example:
+	//  func _(x int) {
+	//  	clear(x)
+	//  }
+	InvalidClear
+)
diff --git a/contrib/go/_std_1.20/src/internal/types/errors/ya.make b/contrib/go/_std_1.20/src/internal/types/errors/ya.make
new file mode 100644
index 0000000000..3fee0fa26e
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/types/errors/ya.make
@@ -0,0 +1,7 @@
+GO_LIBRARY()
+
+SRCS(
+    codes.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/unsafeheader/unsafeheader.go b/contrib/go/_std_1.20/src/internal/unsafeheader/unsafeheader.go
new file mode 100644
index 0000000000..6d092c629a
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/unsafeheader/unsafeheader.go
@@ -0,0 +1,37 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package unsafeheader contains header declarations for the Go runtime's slice
+// and string implementations.
+//
+// This package allows packages that cannot import "reflect" to use types that
+// are tested to be equivalent to reflect.SliceHeader and reflect.StringHeader.
+package unsafeheader
+
+import (
+	"unsafe"
+)
+
+// Slice is the runtime representation of a slice.
+// It cannot be used safely or portably and its representation may
+// change in a later release.
+//
+// Unlike reflect.SliceHeader, its Data field is sufficient to guarantee the
+// data it references will not be garbage collected.
+type Slice struct {
+	Data unsafe.Pointer
+	Len  int
+	Cap  int
+}
+
+// String is the runtime representation of a string.
+// It cannot be used safely or portably and its representation may
+// change in a later release.
+//
+// Unlike reflect.StringHeader, its Data field is sufficient to guarantee the
+// data it references will not be garbage collected.
+type String struct {
+	Data unsafe.Pointer
+	Len  int
+}
diff --git a/contrib/go/_std_1.20/src/internal/unsafeheader/ya.make b/contrib/go/_std_1.20/src/internal/unsafeheader/ya.make
new file mode 100644
index 0000000000..d1319b628f
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/unsafeheader/ya.make
@@ -0,0 +1,7 @@
+GO_LIBRARY()
+
+SRCS(
+    unsafeheader.go
+)
+
+END()
diff --git a/contrib/go/_std_1.20/src/internal/xcoff/ar.go b/contrib/go/_std_1.20/src/internal/xcoff/ar.go
new file mode 100644
index 0000000000..2b432d5e10
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/xcoff/ar.go
@@ -0,0 +1,228 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package xcoff
+
+import (
+	"encoding/binary"
+	"fmt"
+	"io"
+	"os"
+	"strconv"
+	"strings"
+)
+
+const (
+	SAIAMAG   = 0x8
+	AIAFMAG   = "`\n"
+	AIAMAG    = "<aiaff>\n"
+	AIAMAGBIG = "<bigaf>\n"
+
+	// Sizeof
+	FL_HSZ_BIG = 0x80
+	AR_HSZ_BIG = 0x70
+)
+
+type bigarFileHeader struct {
+	Flmagic    [SAIAMAG]byte // Archive magic string
+	Flmemoff   [20]byte      // Member table offset
+	Flgstoff   [20]byte      // 32-bits global symtab offset
+	Flgst64off [20]byte      // 64-bits global symtab offset
+	Flfstmoff  [20]byte      // First member offset
+	Fllstmoff  [20]byte      // Last member offset
+	Flfreeoff  [20]byte      // First member on free list offset
+}
+
+type bigarMemberHeader struct {
+	Arsize   [20]byte // File member size
+	Arnxtmem [20]byte // Next member pointer
+	Arprvmem [20]byte // Previous member pointer
+	Ardate   [12]byte // File member date
+	Aruid    [12]byte // File member uid
+	Argid    [12]byte // File member gid
+	Armode   [12]byte // File member mode (octal)
+	Arnamlen [4]byte  // File member name length
+	// _ar_nam is removed because it's easier to get name without it.
+}
+
+// Archive represents an open AIX big archive.
+type Archive struct {
+	ArchiveHeader
+	Members []*Member
+
+	closer io.Closer
+}
+
+// MemberHeader holds information about a big archive file header
+type ArchiveHeader struct {
+	magic string
+}
+
+// Member represents a member of an AIX big archive.
+type Member struct {
+	MemberHeader
+	sr *io.SectionReader
+}
+
+// MemberHeader holds information about a big archive member
+type MemberHeader struct {
+	Name string
+	Size uint64
+}
+
+// OpenArchive opens the named archive using os.Open and prepares it for use
+// as an AIX big archive.
+func OpenArchive(name string) (*Archive, error) {
+	f, err := os.Open(name)
+	if err != nil {
+		return nil, err
+	}
+	arch, err := NewArchive(f)
+	if err != nil {
+		f.Close()
+		return nil, err
+	}
+	arch.closer = f
+	return arch, nil
+}
+
+// Close closes the Archive.
+// If the Archive was created using NewArchive directly instead of OpenArchive,
+// Close has no effect.
+func (a *Archive) Close() error {
+	var err error
+	if a.closer != nil {
+		err = a.closer.Close()
+		a.closer = nil
+	}
+	return err
+}
+
+// NewArchive creates a new Archive for accessing an AIX big archive in an underlying reader.
+func NewArchive(r io.ReaderAt) (*Archive, error) {
+	parseDecimalBytes := func(b []byte) (int64, error) {
+		return strconv.ParseInt(strings.TrimSpace(string(b)), 10, 64)
+	}
+	sr := io.NewSectionReader(r, 0, 1<<63-1)
+
+	// Read File Header
+	var magic [SAIAMAG]byte
+	if _, err := sr.ReadAt(magic[:], 0); err != nil {
+		return nil, err
+	}
+
+	arch := new(Archive)
+	switch string(magic[:]) {
+	case AIAMAGBIG:
+		arch.magic = string(magic[:])
+	case AIAMAG:
+		return nil, fmt.Errorf("small AIX archive not supported")
+	default:
+		return nil, fmt.Errorf("unrecognised archive magic: 0x%x", magic)
+	}
+
+	var fhdr bigarFileHeader
+	if _, err := sr.Seek(0, io.SeekStart); err != nil {
+		return nil, err
+	}
+	if err := binary.Read(sr, binary.BigEndian, &fhdr); err != nil {
+		return nil, err
+	}
+
+	off, err := parseDecimalBytes(fhdr.Flfstmoff[:])
+	if err != nil {
+		return nil, fmt.Errorf("error parsing offset of first member in archive header(%q); %v", fhdr, err)
+	}
+
+	if off == 0 {
+		// Occurs if the archive is empty.
+		return arch, nil
+	}
+
+	lastoff, err := parseDecimalBytes(fhdr.Fllstmoff[:])
+	if err != nil {
+		return nil, fmt.Errorf("error parsing offset of first member in archive header(%q); %v", fhdr, err)
+	}
+
+	// Read members
+	for {
+		// Read Member Header
+		// The member header is normally 2 bytes larger. But it's easier
+		// to read the name if the header is read without _ar_nam.
+		// However, AIAFMAG must be read afterward.
+		if _, err := sr.Seek(off, io.SeekStart); err != nil {
+			return nil, err
+		}
+
+		var mhdr bigarMemberHeader
+		if err := binary.Read(sr, binary.BigEndian, &mhdr); err != nil {
+			return nil, err
+		}
+
+		member := new(Member)
+		arch.Members = append(arch.Members, member)
+
+		size, err := parseDecimalBytes(mhdr.Arsize[:])
+		if err != nil {
+			return nil, fmt.Errorf("error parsing size in member header(%q); %v", mhdr, err)
+		}
+		member.Size = uint64(size)
+
+		// Read name
+		namlen, err := parseDecimalBytes(mhdr.Arnamlen[:])
+		if err != nil {
+			return nil, fmt.Errorf("error parsing name length in member header(%q); %v", mhdr, err)
+		}
+		name := make([]byte, namlen)
+		if err := binary.Read(sr, binary.BigEndian, name); err != nil {
+			return nil, err
+		}
+		member.Name = string(name)
+
+		fileoff := off + AR_HSZ_BIG + namlen
+		if fileoff&1 != 0 {
+			fileoff++
+			if _, err := sr.Seek(1, io.SeekCurrent); err != nil {
+				return nil, err
+			}
+		}
+
+		// Read AIAFMAG string
+		var fmag [2]byte
+		if err := binary.Read(sr, binary.BigEndian, &fmag); err != nil {
+			return nil, err
+		}
+		if string(fmag[:]) != AIAFMAG {
+			return nil, fmt.Errorf("AIAFMAG not found after member header")
+		}
+
+		fileoff += 2 // Add the two bytes of AIAFMAG
+		member.sr = io.NewSectionReader(sr, fileoff, size)
+
+		if off == lastoff {
+			break
+		}
+		off, err = parseDecimalBytes(mhdr.Arnxtmem[:])
+		if err != nil {
+			return nil, fmt.Errorf("error parsing offset of first member in archive header(%q); %v", fhdr, err)
+		}
+
+	}
+
+	return arch, nil
+
+}
+
+// GetFile returns the XCOFF file defined by member name.
+// FIXME: This doesn't work if an archive has two members with the same
+// name which can occur if a archive has both 32-bits and 64-bits files.
+func (arch *Archive) GetFile(name string) (*File, error) {
+	for _, mem := range arch.Members {
+		if mem.Name == name {
+			return NewFile(mem.sr)
+		}
+	}
+	return nil, fmt.Errorf("unknown member %s in archive", name)
+
+}
diff --git a/contrib/go/_std_1.20/src/internal/xcoff/file.go b/contrib/go/_std_1.20/src/internal/xcoff/file.go
new file mode 100644
index 0000000000..e859de932a
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/xcoff/file.go
@@ -0,0 +1,692 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package xcoff implements access to XCOFF (Extended Common Object File Format) files.
+package xcoff
+
+import (
+	"debug/dwarf"
+	"encoding/binary"
+	"fmt"
+	"internal/saferio"
+	"io"
+	"os"
+	"strings"
+)
+
+// SectionHeader holds information about an XCOFF section header.
+type SectionHeader struct {
+	Name           string
+	VirtualAddress uint64
+	Size           uint64
+	Type           uint32
+	Relptr         uint64
+	Nreloc         uint32
+}
+
+type Section struct {
+	SectionHeader
+	Relocs []Reloc
+	io.ReaderAt
+	sr *io.SectionReader
+}
+
+// AuxiliaryCSect holds information about an XCOFF symbol in an AUX_CSECT entry.
+type AuxiliaryCSect struct {
+	Length              int64
+	StorageMappingClass int
+	SymbolType          int
+}
+
+// AuxiliaryFcn holds information about an XCOFF symbol in an AUX_FCN entry.
+type AuxiliaryFcn struct {
+	Size int64
+}
+
+type Symbol struct {
+	Name          string
+	Value         uint64
+	SectionNumber int
+	StorageClass  int
+	AuxFcn        AuxiliaryFcn
+	AuxCSect      AuxiliaryCSect
+}
+
+type Reloc struct {
+	VirtualAddress   uint64
+	Symbol           *Symbol
+	Signed           bool
+	InstructionFixed bool
+	Length           uint8
+	Type             uint8
+}
+
+// ImportedSymbol holds information about an imported XCOFF symbol.
+type ImportedSymbol struct {
+	Name    string
+	Library string
+}
+
+// FileHeader holds information about an XCOFF file header.
+type FileHeader struct {
+	TargetMachine uint16
+}
+
+// A File represents an open XCOFF file.
+type File struct {
+	FileHeader
+	Sections     []*Section
+	Symbols      []*Symbol
+	StringTable  []byte
+	LibraryPaths []string
+
+	closer io.Closer
+}
+
+// Open opens the named file using os.Open and prepares it for use as an XCOFF binary.
+func Open(name string) (*File, error) {
+	f, err := os.Open(name)
+	if err != nil {
+		return nil, err
+	}
+	ff, err := NewFile(f)
+	if err != nil {
+		f.Close()
+		return nil, err
+	}
+	ff.closer = f
+	return ff, nil
+}
+
+// Close closes the File.
+// If the File was created using NewFile directly instead of Open,
+// Close has no effect.
+func (f *File) Close() error {
+	var err error
+	if f.closer != nil {
+		err = f.closer.Close()
+		f.closer = nil
+	}
+	return err
+}
+
+// Section returns the first section with the given name, or nil if no such
+// section exists.
+// Xcoff have section's name limited to 8 bytes. Some sections like .gosymtab
+// can be trunked but this method will still find them.
+func (f *File) Section(name string) *Section {
+	for _, s := range f.Sections {
+		if s.Name == name || (len(name) > 8 && s.Name == name[:8]) {
+			return s
+		}
+	}
+	return nil
+}
+
+// SectionByType returns the first section in f with the
+// given type, or nil if there is no such section.
+func (f *File) SectionByType(typ uint32) *Section {
+	for _, s := range f.Sections {
+		if s.Type == typ {
+			return s
+		}
+	}
+	return nil
+}
+
+// cstring converts ASCII byte sequence b to string.
+// It stops once it finds 0 or reaches end of b.
+func cstring(b []byte) string {
+	var i int
+	for i = 0; i < len(b) && b[i] != 0; i++ {
+	}
+	return string(b[:i])
+}
+
+// getString extracts a string from an XCOFF string table.
+func getString(st []byte, offset uint32) (string, bool) {
+	if offset < 4 || int(offset) >= len(st) {
+		return "", false
+	}
+	return cstring(st[offset:]), true
+}
+
+// NewFile creates a new File for accessing an XCOFF binary in an underlying reader.
+func NewFile(r io.ReaderAt) (*File, error) {
+	sr := io.NewSectionReader(r, 0, 1<<63-1)
+	// Read XCOFF target machine
+	var magic uint16
+	if err := binary.Read(sr, binary.BigEndian, &magic); err != nil {
+		return nil, err
+	}
+	if magic != U802TOCMAGIC && magic != U64_TOCMAGIC {
+		return nil, fmt.Errorf("unrecognised XCOFF magic: 0x%x", magic)
+	}
+
+	f := new(File)
+	f.TargetMachine = magic
+
+	// Read XCOFF file header
+	if _, err := sr.Seek(0, io.SeekStart); err != nil {
+		return nil, err
+	}
+	var nscns uint16
+	var symptr uint64
+	var nsyms int32
+	var opthdr uint16
+	var hdrsz int
+	switch f.TargetMachine {
+	case U802TOCMAGIC:
+		fhdr := new(FileHeader32)
+		if err := binary.Read(sr, binary.BigEndian, fhdr); err != nil {
+			return nil, err
+		}
+		nscns = fhdr.Fnscns
+		symptr = uint64(fhdr.Fsymptr)
+		nsyms = fhdr.Fnsyms
+		opthdr = fhdr.Fopthdr
+		hdrsz = FILHSZ_32
+	case U64_TOCMAGIC:
+		fhdr := new(FileHeader64)
+		if err := binary.Read(sr, binary.BigEndian, fhdr); err != nil {
+			return nil, err
+		}
+		nscns = fhdr.Fnscns
+		symptr = fhdr.Fsymptr
+		nsyms = fhdr.Fnsyms
+		opthdr = fhdr.Fopthdr
+		hdrsz = FILHSZ_64
+	}
+
+	if symptr == 0 || nsyms <= 0 {
+		return nil, fmt.Errorf("no symbol table")
+	}
+
+	// Read string table (located right after symbol table).
+	offset := symptr + uint64(nsyms)*SYMESZ
+	if _, err := sr.Seek(int64(offset), io.SeekStart); err != nil {
+		return nil, err
+	}
+	// The first 4 bytes contain the length (in bytes).
+	var l uint32
+	if err := binary.Read(sr, binary.BigEndian, &l); err != nil {
+		return nil, err
+	}
+	if l > 4 {
+		st, err := saferio.ReadDataAt(sr, uint64(l), int64(offset))
+		if err != nil {
+			return nil, err
+		}
+		f.StringTable = st
+	}
+
+	// Read section headers
+	if _, err := sr.Seek(int64(hdrsz)+int64(opthdr), io.SeekStart); err != nil {
+		return nil, err
+	}
+	f.Sections = make([]*Section, nscns)
+	for i := 0; i < int(nscns); i++ {
+		var scnptr uint64
+		s := new(Section)
+		switch f.TargetMachine {
+		case U802TOCMAGIC:
+			shdr := new(SectionHeader32)
+			if err := binary.Read(sr, binary.BigEndian, shdr); err != nil {
+				return nil, err
+			}
+			s.Name = cstring(shdr.Sname[:])
+			s.VirtualAddress = uint64(shdr.Svaddr)
+			s.Size = uint64(shdr.Ssize)
+			scnptr = uint64(shdr.Sscnptr)
+			s.Type = shdr.Sflags
+			s.Relptr = uint64(shdr.Srelptr)
+			s.Nreloc = uint32(shdr.Snreloc)
+		case U64_TOCMAGIC:
+			shdr := new(SectionHeader64)
+			if err := binary.Read(sr, binary.BigEndian, shdr); err != nil {
+				return nil, err
+			}
+			s.Name = cstring(shdr.Sname[:])
+			s.VirtualAddress = shdr.Svaddr
+			s.Size = shdr.Ssize
+			scnptr = shdr.Sscnptr
+			s.Type = shdr.Sflags
+			s.Relptr = shdr.Srelptr
+			s.Nreloc = shdr.Snreloc
+		}
+		r2 := r
+		if scnptr == 0 { // .bss must have all 0s
+			r2 = zeroReaderAt{}
+		}
+		s.sr = io.NewSectionReader(r2, int64(scnptr), int64(s.Size))
+		s.ReaderAt = s.sr
+		f.Sections[i] = s
+	}
+
+	// Symbol map needed by relocation
+	var idxToSym = make(map[int]*Symbol)
+
+	// Read symbol table
+	if _, err := sr.Seek(int64(symptr), io.SeekStart); err != nil {
+		return nil, err
+	}
+	f.Symbols = make([]*Symbol, 0)
+	for i := 0; i < int(nsyms); i++ {
+		var numaux int
+		var ok, needAuxFcn bool
+		sym := new(Symbol)
+		switch f.TargetMachine {
+		case U802TOCMAGIC:
+			se := new(SymEnt32)
+			if err := binary.Read(sr, binary.BigEndian, se); err != nil {
+				return nil, err
+			}
+			numaux = int(se.Nnumaux)
+			if numaux < 0 {
+				return nil, fmt.Errorf("malformed symbol table, invalid number of aux symbols")
+			}
+			sym.SectionNumber = int(se.Nscnum)
+			sym.StorageClass = int(se.Nsclass)
+			sym.Value = uint64(se.Nvalue)
+			needAuxFcn = se.Ntype&SYM_TYPE_FUNC != 0 && numaux > 1
+			zeroes := binary.BigEndian.Uint32(se.Nname[:4])
+			if zeroes != 0 {
+				sym.Name = cstring(se.Nname[:])
+			} else {
+				offset := binary.BigEndian.Uint32(se.Nname[4:])
+				sym.Name, ok = getString(f.StringTable, offset)
+				if !ok {
+					goto skip
+				}
+			}
+		case U64_TOCMAGIC:
+			se := new(SymEnt64)
+			if err := binary.Read(sr, binary.BigEndian, se); err != nil {
+				return nil, err
+			}
+			numaux = int(se.Nnumaux)
+			if numaux < 0 {
+				return nil, fmt.Errorf("malformed symbol table, invalid number of aux symbols")
+			}
+			sym.SectionNumber = int(se.Nscnum)
+			sym.StorageClass = int(se.Nsclass)
+			sym.Value = se.Nvalue
+			needAuxFcn = se.Ntype&SYM_TYPE_FUNC != 0 && numaux > 1
+			sym.Name, ok = getString(f.StringTable, se.Noffset)
+			if !ok {
+				goto skip
+			}
+		}
+		if sym.StorageClass != C_EXT && sym.StorageClass != C_WEAKEXT && sym.StorageClass != C_HIDEXT {
+			goto skip
+		}
+		// Must have at least one csect auxiliary entry.
+		if numaux < 1 || i+numaux >= int(nsyms) {
+			goto skip
+		}
+
+		if sym.SectionNumber > int(nscns) {
+			goto skip
+		}
+		if sym.SectionNumber == 0 {
+			sym.Value = 0
+		} else {
+			sym.Value -= f.Sections[sym.SectionNumber-1].VirtualAddress
+		}
+
+		idxToSym[i] = sym
+
+		// If this symbol is a function, it must retrieve its size from
+		// its AUX_FCN entry.
+		// It can happen that a function symbol doesn't have any AUX_FCN.
+		// In this case, needAuxFcn is false and their size will be set to 0.
+		if needAuxFcn {
+			switch f.TargetMachine {
+			case U802TOCMAGIC:
+				aux := new(AuxFcn32)
+				if err := binary.Read(sr, binary.BigEndian, aux); err != nil {
+					return nil, err
+				}
+				sym.AuxFcn.Size = int64(aux.Xfsize)
+			case U64_TOCMAGIC:
+				aux := new(AuxFcn64)
+				if err := binary.Read(sr, binary.BigEndian, aux); err != nil {
+					return nil, err
+				}
+				sym.AuxFcn.Size = int64(aux.Xfsize)
+			}
+		}
+
+		// Read csect auxiliary entry (by convention, it is the last).
+		if !needAuxFcn {
+			if _, err := sr.Seek(int64(numaux-1)*SYMESZ, io.SeekCurrent); err != nil {
+				return nil, err
+			}
+		}
+		i += numaux
+		numaux = 0
+		switch f.TargetMachine {
+		case U802TOCMAGIC:
+			aux := new(AuxCSect32)
+			if err := binary.Read(sr, binary.BigEndian, aux); err != nil {
+				return nil, err
+			}
+			sym.AuxCSect.SymbolType = int(aux.Xsmtyp & 0x7)
+			sym.AuxCSect.StorageMappingClass = int(aux.Xsmclas)
+			sym.AuxCSect.Length = int64(aux.Xscnlen)
+		case U64_TOCMAGIC:
+			aux := new(AuxCSect64)
+			if err := binary.Read(sr, binary.BigEndian, aux); err != nil {
+				return nil, err
+			}
+			sym.AuxCSect.SymbolType = int(aux.Xsmtyp & 0x7)
+			sym.AuxCSect.StorageMappingClass = int(aux.Xsmclas)
+			sym.AuxCSect.Length = int64(aux.Xscnlenhi)<<32 | int64(aux.Xscnlenlo)
+		}
+		f.Symbols = append(f.Symbols, sym)
+	skip:
+		i += numaux // Skip auxiliary entries
+		if _, err := sr.Seek(int64(numaux)*SYMESZ, io.SeekCurrent); err != nil {
+			return nil, err
+		}
+	}
+
+	// Read relocations
+	// Only for .data or .text section
+	for _, sect := range f.Sections {
+		if sect.Type != STYP_TEXT && sect.Type != STYP_DATA {
+			continue
+		}
+		sect.Relocs = make([]Reloc, sect.Nreloc)
+		if sect.Relptr == 0 {
+			continue
+		}
+		if _, err := sr.Seek(int64(sect.Relptr), io.SeekStart); err != nil {
+			return nil, err
+		}
+		for i := uint32(0); i < sect.Nreloc; i++ {
+			switch f.TargetMachine {
+			case U802TOCMAGIC:
+				rel := new(Reloc32)
+				if err := binary.Read(sr, binary.BigEndian, rel); err != nil {
+					return nil, err
+				}
+				sect.Relocs[i].VirtualAddress = uint64(rel.Rvaddr)
+				sect.Relocs[i].Symbol = idxToSym[int(rel.Rsymndx)]
+				sect.Relocs[i].Type = rel.Rtype
+				sect.Relocs[i].Length = rel.Rsize&0x3F + 1
+
+				if rel.Rsize&0x80 != 0 {
+					sect.Relocs[i].Signed = true
+				}
+				if rel.Rsize&0x40 != 0 {
+					sect.Relocs[i].InstructionFixed = true
+				}
+
+			case U64_TOCMAGIC:
+				rel := new(Reloc64)
+				if err := binary.Read(sr, binary.BigEndian, rel); err != nil {
+					return nil, err
+				}
+				sect.Relocs[i].VirtualAddress = rel.Rvaddr
+				sect.Relocs[i].Symbol = idxToSym[int(rel.Rsymndx)]
+				sect.Relocs[i].Type = rel.Rtype
+				sect.Relocs[i].Length = rel.Rsize&0x3F + 1
+				if rel.Rsize&0x80 != 0 {
+					sect.Relocs[i].Signed = true
+				}
+				if rel.Rsize&0x40 != 0 {
+					sect.Relocs[i].InstructionFixed = true
+				}
+			}
+		}
+	}
+
+	return f, nil
+}
+
+// zeroReaderAt is ReaderAt that reads 0s.
+type zeroReaderAt struct{}
+
+// ReadAt writes len(p) 0s into p.
+func (w zeroReaderAt) ReadAt(p []byte, off int64) (n int, err error) {
+	for i := range p {
+		p[i] = 0
+	}
+	return len(p), nil
+}
+
+// Data reads and returns the contents of the XCOFF section s.
+func (s *Section) Data() ([]byte, error) {
+	dat := make([]byte, s.sr.Size())
+	n, err := s.sr.ReadAt(dat, 0)
+	if n == len(dat) {
+		err = nil
+	}
+	return dat[:n], err
+}
+
+// CSect reads and returns the contents of a csect.
+func (f *File) CSect(name string) []byte {
+	for _, sym := range f.Symbols {
+		if sym.Name == name && sym.AuxCSect.SymbolType == XTY_SD {
+			if i := sym.SectionNumber - 1; 0 <= i && i < len(f.Sections) {
+				s := f.Sections[i]
+				if sym.Value+uint64(sym.AuxCSect.Length) <= s.Size {
+					dat := make([]byte, sym.AuxCSect.Length)
+					_, err := s.sr.ReadAt(dat, int64(sym.Value))
+					if err != nil {
+						return nil
+					}
+					return dat
+				}
+			}
+			break
+		}
+	}
+	return nil
+}
+
+func (f *File) DWARF() (*dwarf.Data, error) {
+	// There are many other DWARF sections, but these
+	// are the ones the debug/dwarf package uses.
+	// Don't bother loading others.
+	var subtypes = [...]uint32{SSUBTYP_DWABREV, SSUBTYP_DWINFO, SSUBTYP_DWLINE, SSUBTYP_DWRNGES, SSUBTYP_DWSTR}
+	var dat [len(subtypes)][]byte
+	for i, subtype := range subtypes {
+		s := f.SectionByType(STYP_DWARF | subtype)
+		if s != nil {
+			b, err := s.Data()
+			if err != nil && uint64(len(b)) < s.Size {
+				return nil, err
+			}
+			dat[i] = b
+		}
+	}
+
+	abbrev, info, line, ranges, str := dat[0], dat[1], dat[2], dat[3], dat[4]
+	return dwarf.New(abbrev, nil, nil, info, line, nil, ranges, str)
+}
+
+// readImportID returns the import file IDs stored inside the .loader section.
+// Library name pattern is either path/base/member or base/member
+func (f *File) readImportIDs(s *Section) ([]string, error) {
+	// Read loader header
+	if _, err := s.sr.Seek(0, io.SeekStart); err != nil {
+		return nil, err
+	}
+	var istlen uint32
+	var nimpid int32
+	var impoff uint64
+	switch f.TargetMachine {
+	case U802TOCMAGIC:
+		lhdr := new(LoaderHeader32)
+		if err := binary.Read(s.sr, binary.BigEndian, lhdr); err != nil {
+			return nil, err
+		}
+		istlen = lhdr.Listlen
+		nimpid = lhdr.Lnimpid
+		impoff = uint64(lhdr.Limpoff)
+	case U64_TOCMAGIC:
+		lhdr := new(LoaderHeader64)
+		if err := binary.Read(s.sr, binary.BigEndian, lhdr); err != nil {
+			return nil, err
+		}
+		istlen = lhdr.Listlen
+		nimpid = lhdr.Lnimpid
+		impoff = lhdr.Limpoff
+	}
+
+	// Read loader import file ID table
+	if _, err := s.sr.Seek(int64(impoff), io.SeekStart); err != nil {
+		return nil, err
+	}
+	table := make([]byte, istlen)
+	if _, err := io.ReadFull(s.sr, table); err != nil {
+		return nil, err
+	}
+
+	offset := 0
+	// First import file ID is the default LIBPATH value
+	libpath := cstring(table[offset:])
+	f.LibraryPaths = strings.Split(libpath, ":")
+	offset += len(libpath) + 3 // 3 null bytes
+	all := make([]string, 0)
+	for i := 1; i < int(nimpid); i++ {
+		impidpath := cstring(table[offset:])
+		offset += len(impidpath) + 1
+		impidbase := cstring(table[offset:])
+		offset += len(impidbase) + 1
+		impidmem := cstring(table[offset:])
+		offset += len(impidmem) + 1
+		var path string
+		if len(impidpath) > 0 {
+			path = impidpath + "/" + impidbase + "/" + impidmem
+		} else {
+			path = impidbase + "/" + impidmem
+		}
+		all = append(all, path)
+	}
+
+	return all, nil
+}
+
+// ImportedSymbols returns the names of all symbols
+// referred to by the binary f that are expected to be
+// satisfied by other libraries at dynamic load time.
+// It does not return weak symbols.
+func (f *File) ImportedSymbols() ([]ImportedSymbol, error) {
+	s := f.SectionByType(STYP_LOADER)
+	if s == nil {
+		return nil, nil
+	}
+	// Read loader header
+	if _, err := s.sr.Seek(0, io.SeekStart); err != nil {
+		return nil, err
+	}
+	var stlen uint32
+	var stoff uint64
+	var nsyms int32
+	var symoff uint64
+	switch f.TargetMachine {
+	case U802TOCMAGIC:
+		lhdr := new(LoaderHeader32)
+		if err := binary.Read(s.sr, binary.BigEndian, lhdr); err != nil {
+			return nil, err
+		}
+		stlen = lhdr.Lstlen
+		stoff = uint64(lhdr.Lstoff)
+		nsyms = lhdr.Lnsyms
+		symoff = LDHDRSZ_32
+	case U64_TOCMAGIC:
+		lhdr := new(LoaderHeader64)
+		if err := binary.Read(s.sr, binary.BigEndian, lhdr); err != nil {
+			return nil, err
+		}
+		stlen = lhdr.Lstlen
+		stoff = lhdr.Lstoff
+		nsyms = lhdr.Lnsyms
+		symoff = lhdr.Lsymoff
+	}
+
+	// Read loader section string table
+	if _, err := s.sr.Seek(int64(stoff), io.SeekStart); err != nil {
+		return nil, err
+	}
+	st := make([]byte, stlen)
+	if _, err := io.ReadFull(s.sr, st); err != nil {
+		return nil, err
+	}
+
+	// Read imported libraries
+	libs, err := f.readImportIDs(s)
+	if err != nil {
+		return nil, err
+	}
+
+	// Read loader symbol table
+	if _, err := s.sr.Seek(int64(symoff), io.SeekStart); err != nil {
+		return nil, err
+	}
+	all := make([]ImportedSymbol, 0)
+	for i := 0; i < int(nsyms); i++ {
+		var name string
+		var ifile int32
+		var ok bool
+		switch f.TargetMachine {
+		case U802TOCMAGIC:
+			ldsym := new(LoaderSymbol32)
+			if err := binary.Read(s.sr, binary.BigEndian, ldsym); err != nil {
+				return nil, err
+			}
+			if ldsym.Lsmtype&0x40 == 0 {
+				continue // Imported symbols only
+			}
+			zeroes := binary.BigEndian.Uint32(ldsym.Lname[:4])
+			if zeroes != 0 {
+				name = cstring(ldsym.Lname[:])
+			} else {
+				offset := binary.BigEndian.Uint32(ldsym.Lname[4:])
+				name, ok = getString(st, offset)
+				if !ok {
+					continue
+				}
+			}
+			ifile = ldsym.Lifile
+		case U64_TOCMAGIC:
+			ldsym := new(LoaderSymbol64)
+			if err := binary.Read(s.sr, binary.BigEndian, ldsym); err != nil {
+				return nil, err
+			}
+			if ldsym.Lsmtype&0x40 == 0 {
+				continue // Imported symbols only
+			}
+			name, ok = getString(st, ldsym.Loffset)
+			if !ok {
+				continue
+			}
+			ifile = ldsym.Lifile
+		}
+		var sym ImportedSymbol
+		sym.Name = name
+		if ifile >= 1 && int(ifile) <= len(libs) {
+			sym.Library = libs[ifile-1]
+		}
+		all = append(all, sym)
+	}
+
+	return all, nil
+}
+
+// ImportedLibraries returns the names of all libraries
+// referred to by the binary f that are expected to be
+// linked with the binary at dynamic link time.
+func (f *File) ImportedLibraries() ([]string, error) {
+	s := f.SectionByType(STYP_LOADER)
+	if s == nil {
+		return nil, nil
+	}
+	all, err := f.readImportIDs(s)
+	return all, err
+}
diff --git a/contrib/go/_std_1.20/src/internal/xcoff/xcoff.go b/contrib/go/_std_1.20/src/internal/xcoff/xcoff.go
new file mode 100644
index 0000000000..f8465d7289
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/xcoff/xcoff.go
@@ -0,0 +1,367 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package xcoff
+
+// File Header.
+type FileHeader32 struct {
+	Fmagic   uint16 // Target machine
+	Fnscns   uint16 // Number of sections
+	Ftimedat int32  // Time and date of file creation
+	Fsymptr  uint32 // Byte offset to symbol table start
+	Fnsyms   int32  // Number of entries in symbol table
+	Fopthdr  uint16 // Number of bytes in optional header
+	Fflags   uint16 // Flags
+}
+
+type FileHeader64 struct {
+	Fmagic   uint16 // Target machine
+	Fnscns   uint16 // Number of sections
+	Ftimedat int32  // Time and date of file creation
+	Fsymptr  uint64 // Byte offset to symbol table start
+	Fopthdr  uint16 // Number of bytes in optional header
+	Fflags   uint16 // Flags
+	Fnsyms   int32  // Number of entries in symbol table
+}
+
+const (
+	FILHSZ_32 = 20
+	FILHSZ_64 = 24
+)
+const (
+	U802TOCMAGIC = 0737 // AIX 32-bit XCOFF
+	U64_TOCMAGIC = 0767 // AIX 64-bit XCOFF
+)
+
+// Flags that describe the type of the object file.
+const (
+	F_RELFLG    = 0x0001
+	F_EXEC      = 0x0002
+	F_LNNO      = 0x0004
+	F_FDPR_PROF = 0x0010
+	F_FDPR_OPTI = 0x0020
+	F_DSA       = 0x0040
+	F_VARPG     = 0x0100
+	F_DYNLOAD   = 0x1000
+	F_SHROBJ    = 0x2000
+	F_LOADONLY  = 0x4000
+)
+
+// Section Header.
+type SectionHeader32 struct {
+	Sname    [8]byte // Section name
+	Spaddr   uint32  // Physical address
+	Svaddr   uint32  // Virtual address
+	Ssize    uint32  // Section size
+	Sscnptr  uint32  // Offset in file to raw data for section
+	Srelptr  uint32  // Offset in file to relocation entries for section
+	Slnnoptr uint32  // Offset in file to line number entries for section
+	Snreloc  uint16  // Number of relocation entries
+	Snlnno   uint16  // Number of line number entries
+	Sflags   uint32  // Flags to define the section type
+}
+
+type SectionHeader64 struct {
+	Sname    [8]byte // Section name
+	Spaddr   uint64  // Physical address
+	Svaddr   uint64  // Virtual address
+	Ssize    uint64  // Section size
+	Sscnptr  uint64  // Offset in file to raw data for section
+	Srelptr  uint64  // Offset in file to relocation entries for section
+	Slnnoptr uint64  // Offset in file to line number entries for section
+	Snreloc  uint32  // Number of relocation entries
+	Snlnno   uint32  // Number of line number entries
+	Sflags   uint32  // Flags to define the section type
+	Spad     uint32  // Needs to be 72 bytes long
+}
+
+// Flags defining the section type.
+const (
+	STYP_DWARF  = 0x0010
+	STYP_TEXT   = 0x0020
+	STYP_DATA   = 0x0040
+	STYP_BSS    = 0x0080
+	STYP_EXCEPT = 0x0100
+	STYP_INFO   = 0x0200
+	STYP_TDATA  = 0x0400
+	STYP_TBSS   = 0x0800
+	STYP_LOADER = 0x1000
+	STYP_DEBUG  = 0x2000
+	STYP_TYPCHK = 0x4000
+	STYP_OVRFLO = 0x8000
+)
+const (
+	SSUBTYP_DWINFO  = 0x10000 // DWARF info section
+	SSUBTYP_DWLINE  = 0x20000 // DWARF line-number section
+	SSUBTYP_DWPBNMS = 0x30000 // DWARF public names section
+	SSUBTYP_DWPBTYP = 0x40000 // DWARF public types section
+	SSUBTYP_DWARNGE = 0x50000 // DWARF aranges section
+	SSUBTYP_DWABREV = 0x60000 // DWARF abbreviation section
+	SSUBTYP_DWSTR   = 0x70000 // DWARF strings section
+	SSUBTYP_DWRNGES = 0x80000 // DWARF ranges section
+	SSUBTYP_DWLOC   = 0x90000 // DWARF location lists section
+	SSUBTYP_DWFRAME = 0xA0000 // DWARF frames section
+	SSUBTYP_DWMAC   = 0xB0000 // DWARF macros section
+)
+
+// Symbol Table Entry.
+type SymEnt32 struct {
+	Nname   [8]byte // Symbol name
+	Nvalue  uint32  // Symbol value
+	Nscnum  int16   // Section number of symbol
+	Ntype   uint16  // Basic and derived type specification
+	Nsclass int8    // Storage class of symbol
+	Nnumaux int8    // Number of auxiliary entries
+}
+
+type SymEnt64 struct {
+	Nvalue  uint64 // Symbol value
+	Noffset uint32 // Offset of the name in string table or .debug section
+	Nscnum  int16  // Section number of symbol
+	Ntype   uint16 // Basic and derived type specification
+	Nsclass int8   // Storage class of symbol
+	Nnumaux int8   // Number of auxiliary entries
+}
+
+const SYMESZ = 18
+
+const (
+	// Nscnum
+	N_DEBUG = -2
+	N_ABS   = -1
+	N_UNDEF = 0
+
+	//Ntype
+	SYM_V_INTERNAL  = 0x1000
+	SYM_V_HIDDEN    = 0x2000
+	SYM_V_PROTECTED = 0x3000
+	SYM_V_EXPORTED  = 0x4000
+	SYM_TYPE_FUNC   = 0x0020 // is function
+)
+
+// Storage Class.
+const (
+	C_NULL    = 0   // Symbol table entry marked for deletion
+	C_EXT     = 2   // External symbol
+	C_STAT    = 3   // Static symbol
+	C_BLOCK   = 100 // Beginning or end of inner block
+	C_FCN     = 101 // Beginning or end of function
+	C_FILE    = 103 // Source file name and compiler information
+	C_HIDEXT  = 107 // Unnamed external symbol
+	C_BINCL   = 108 // Beginning of include file
+	C_EINCL   = 109 // End of include file
+	C_WEAKEXT = 111 // Weak external symbol
+	C_DWARF   = 112 // DWARF symbol
+	C_GSYM    = 128 // Global variable
+	C_LSYM    = 129 // Automatic variable allocated on stack
+	C_PSYM    = 130 // Argument to subroutine allocated on stack
+	C_RSYM    = 131 // Register variable
+	C_RPSYM   = 132 // Argument to function or procedure stored in register
+	C_STSYM   = 133 // Statically allocated symbol
+	C_BCOMM   = 135 // Beginning of common block
+	C_ECOML   = 136 // Local member of common block
+	C_ECOMM   = 137 // End of common block
+	C_DECL    = 140 // Declaration of object
+	C_ENTRY   = 141 // Alternate entry
+	C_FUN     = 142 // Function or procedure
+	C_BSTAT   = 143 // Beginning of static block
+	C_ESTAT   = 144 // End of static block
+	C_GTLS    = 145 // Global thread-local variable
+	C_STTLS   = 146 // Static thread-local variable
+)
+
+// File Auxiliary Entry
+type AuxFile64 struct {
+	Xfname   [8]byte // Name or offset inside string table
+	Xftype   uint8   // Source file string type
+	Xauxtype uint8   // Type of auxiliary entry
+}
+
+// Function Auxiliary Entry
+type AuxFcn32 struct {
+	Xexptr   uint32 // File offset to exception table entry
+	Xfsize   uint32 // Size of function in bytes
+	Xlnnoptr uint32 // File pointer to line number
+	Xendndx  uint32 // Symbol table index of next entry
+	Xpad     uint16 // Unused
+}
+type AuxFcn64 struct {
+	Xlnnoptr uint64 // File pointer to line number
+	Xfsize   uint32 // Size of function in bytes
+	Xendndx  uint32 // Symbol table index of next entry
+	Xpad     uint8  // Unused
+	Xauxtype uint8  // Type of auxiliary entry
+}
+
+type AuxSect64 struct {
+	Xscnlen  uint64 // section length
+	Xnreloc  uint64 // Num RLDs
+	pad      uint8
+	Xauxtype uint8 // Type of auxiliary entry
+}
+
+// csect Auxiliary Entry.
+type AuxCSect32 struct {
+	Xscnlen   int32  // Length or symbol table index
+	Xparmhash uint32 // Offset of parameter type-check string
+	Xsnhash   uint16 // .typchk section number
+	Xsmtyp    uint8  // Symbol alignment and type
+	Xsmclas   uint8  // Storage-mapping class
+	Xstab     uint32 // Reserved
+	Xsnstab   uint16 // Reserved
+}
+
+type AuxCSect64 struct {
+	Xscnlenlo uint32 // Lower 4 bytes of length or symbol table index
+	Xparmhash uint32 // Offset of parameter type-check string
+	Xsnhash   uint16 // .typchk section number
+	Xsmtyp    uint8  // Symbol alignment and type
+	Xsmclas   uint8  // Storage-mapping class
+	Xscnlenhi int32  // Upper 4 bytes of length or symbol table index
+	Xpad      uint8  // Unused
+	Xauxtype  uint8  // Type of auxiliary entry
+}
+
+// Auxiliary type
+const (
+	_AUX_EXCEPT = 255
+	_AUX_FCN    = 254
+	_AUX_SYM    = 253
+	_AUX_FILE   = 252
+	_AUX_CSECT  = 251
+	_AUX_SECT   = 250
+)
+
+// Symbol type field.
+const (
+	XTY_ER = 0 // External reference
+	XTY_SD = 1 // Section definition
+	XTY_LD = 2 // Label definition
+	XTY_CM = 3 // Common csect definition
+)
+
+// Defines for File auxiliary definitions: x_ftype field of x_file
+const (
+	XFT_FN = 0   // Source File Name
+	XFT_CT = 1   // Compile Time Stamp
+	XFT_CV = 2   // Compiler Version Number
+	XFT_CD = 128 // Compiler Defined Information
+)
+
+// Storage-mapping class.
+const (
+	XMC_PR     = 0  // Program code
+	XMC_RO     = 1  // Read-only constant
+	XMC_DB     = 2  // Debug dictionary table
+	XMC_TC     = 3  // TOC entry
+	XMC_UA     = 4  // Unclassified
+	XMC_RW     = 5  // Read/Write data
+	XMC_GL     = 6  // Global linkage
+	XMC_XO     = 7  // Extended operation
+	XMC_SV     = 8  // 32-bit supervisor call descriptor
+	XMC_BS     = 9  // BSS class
+	XMC_DS     = 10 // Function descriptor
+	XMC_UC     = 11 // Unnamed FORTRAN common
+	XMC_TC0    = 15 // TOC anchor
+	XMC_TD     = 16 // Scalar data entry in the TOC
+	XMC_SV64   = 17 // 64-bit supervisor call descriptor
+	XMC_SV3264 = 18 // Supervisor call descriptor for both 32-bit and 64-bit
+	XMC_TL     = 20 // Read/Write thread-local data
+	XMC_UL     = 21 // Read/Write thread-local data (.tbss)
+	XMC_TE     = 22 // TOC entry
+)
+
+// Loader Header.
+type LoaderHeader32 struct {
+	Lversion int32  // Loader section version number
+	Lnsyms   int32  // Number of symbol table entries
+	Lnreloc  int32  // Number of relocation table entries
+	Listlen  uint32 // Length of import file ID string table
+	Lnimpid  int32  // Number of import file IDs
+	Limpoff  uint32 // Offset to start of import file IDs
+	Lstlen   uint32 // Length of string table
+	Lstoff   uint32 // Offset to start of string table
+}
+
+type LoaderHeader64 struct {
+	Lversion int32  // Loader section version number
+	Lnsyms   int32  // Number of symbol table entries
+	Lnreloc  int32  // Number of relocation table entries
+	Listlen  uint32 // Length of import file ID string table
+	Lnimpid  int32  // Number of import file IDs
+	Lstlen   uint32 // Length of string table
+	Limpoff  uint64 // Offset to start of import file IDs
+	Lstoff   uint64 // Offset to start of string table
+	Lsymoff  uint64 // Offset to start of symbol table
+	Lrldoff  uint64 // Offset to start of relocation entries
+}
+
+const (
+	LDHDRSZ_32 = 32
+	LDHDRSZ_64 = 56
+)
+
+// Loader Symbol.
+type LoaderSymbol32 struct {
+	Lname   [8]byte // Symbol name or byte offset into string table
+	Lvalue  uint32  // Address field
+	Lscnum  int16   // Section number containing symbol
+	Lsmtype int8    // Symbol type, export, import flags
+	Lsmclas int8    // Symbol storage class
+	Lifile  int32   // Import file ID; ordinal of import file IDs
+	Lparm   uint32  // Parameter type-check field
+}
+
+type LoaderSymbol64 struct {
+	Lvalue  uint64 // Address field
+	Loffset uint32 // Byte offset into string table of symbol name
+	Lscnum  int16  // Section number containing symbol
+	Lsmtype int8   // Symbol type, export, import flags
+	Lsmclas int8   // Symbol storage class
+	Lifile  int32  // Import file ID; ordinal of import file IDs
+	Lparm   uint32 // Parameter type-check field
+}
+
+type Reloc32 struct {
+	Rvaddr  uint32 // (virtual) address of reference
+	Rsymndx uint32 // Index into symbol table
+	Rsize   uint8  // Sign and reloc bit len
+	Rtype   uint8  // Toc relocation type
+}
+
+type Reloc64 struct {
+	Rvaddr  uint64 // (virtual) address of reference
+	Rsymndx uint32 // Index into symbol table
+	Rsize   uint8  // Sign and reloc bit len
+	Rtype   uint8  // Toc relocation type
+}
+
+const (
+	R_POS = 0x00 // A(sym) Positive Relocation
+	R_NEG = 0x01 // -A(sym) Negative Relocation
+	R_REL = 0x02 // A(sym-*) Relative to self
+	R_TOC = 0x03 // A(sym-TOC) Relative to TOC
+	R_TRL = 0x12 // A(sym-TOC) TOC Relative indirect load.
+
+	R_TRLA = 0x13 // A(sym-TOC) TOC Rel load address. modifiable inst
+	R_GL   = 0x05 // A(external TOC of sym) Global Linkage
+	R_TCL  = 0x06 // A(local TOC of sym) Local object TOC address
+	R_RL   = 0x0C // A(sym) Pos indirect load. modifiable instruction
+	R_RLA  = 0x0D // A(sym) Pos Load Address. modifiable instruction
+	R_REF  = 0x0F // AL0(sym) Non relocating ref. No garbage collect
+	R_BA   = 0x08 // A(sym) Branch absolute. Cannot modify instruction
+	R_RBA  = 0x18 // A(sym) Branch absolute. modifiable instruction
+	R_BR   = 0x0A // A(sym-*) Branch rel to self. non modifiable
+	R_RBR  = 0x1A // A(sym-*) Branch rel to self. modifiable instr
+
+	R_TLS    = 0x20 // General-dynamic reference to TLS symbol
+	R_TLS_IE = 0x21 // Initial-exec reference to TLS symbol
+	R_TLS_LD = 0x22 // Local-dynamic reference to TLS symbol
+	R_TLS_LE = 0x23 // Local-exec reference to TLS symbol
+	R_TLSM   = 0x24 // Module reference to TLS symbol
+	R_TLSML  = 0x25 // Module reference to local (own) module
+
+	R_TOCU = 0x30 // Relative to TOC - high order bits
+	R_TOCL = 0x31 // Relative to TOC - low order bits
+)
diff --git a/contrib/go/_std_1.20/src/internal/xcoff/ya.make b/contrib/go/_std_1.20/src/internal/xcoff/ya.make
new file mode 100644
index 0000000000..32bfb9ac56
--- /dev/null
+++ b/contrib/go/_std_1.20/src/internal/xcoff/ya.make
@@ -0,0 +1,9 @@
+GO_LIBRARY()
+
+SRCS(
+    ar.go
+    file.go
+    xcoff.go
+)
+
+END()