swscale: save ebx register when it is not available

Configure checks if the ebx register can be used for asm and it has to
be saved if and only if this is not the case.
Without this the build fails when configuring with --toolchain=hardened
--disable-pic on i386 using gcc 4.8:
error: PIC register clobbered by '%ebx' in 'asm'

In that case gcc 4.8 reserves the ebx register for the GOT needed for
PIE, so it can't be used in asm directly.

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
(cherry picked from commit 319438e2f206036ee0cddf401dd50f3b2a3ae117)
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>

0 files changed, 0 insertions, 0 deletions