configure: improve pkg-config support

This adds helper functions for checking packages with pkg-config
and managing the associated flags.

Note that pkg-config use is still discouraged due to widespread
poor practices resulting in broken flags in many situations.  A
few badly designed packages require flags only obtainable using
pkg-config, and these functions are intended for those cases.

Signed-off-by: Mans Rullgard <mans@mansr.com>
(cherry picked from commit 3f8040db3e13c3dbdf07c74d92ca34817a69f733)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

0 files changed, 0 insertions, 0 deletions