h264: avoid using uninitialized memory in NEON chroma mc

Adapt commit 982b596ea6640bfe218a31f6c3fc542d9fe61c31 for the arm and
aarch64 NEON asm. 5-10% faster on Cortex-A9.
dsputil: Split off global motion compensation bits into a separate context
Merge commit 'f23d26a6864128001b03876b0b92fffe131f2060'

* commit 'f23d26a6864128001b03876b0b92fffe131f2060':
  h264: avoid using uninitialized memory in NEON chroma mc

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit 'fab9df63a3156ffe1f9490aafaea41e03ef60ddf'

* commit 'fab9df63a3156ffe1f9490aafaea41e03ef60ddf':
  dsputil: Split off global motion compensation bits into a separate context

Conflicts:
	libavcodec/dsputil.c
	libavcodec/dsputil.h
	libavcodec/ppc/dsputil_altivec.h
	libavcodec/x86/dsputil_init.c
	libavcodec/x86/dsputil_mmx.c
	libavcodec/x86/dsputil_x86.h

Merged-by: Michael Niedermayer <michaelni@gmx.at>
x86/dsputil: move put_signed_pixels_clamped out of bswapdsp.asm

It's still a dsputil function

Signed-off-by: James Almer <jamrial@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
libavcodec/wmalosslessdec: add missing emms

prevent failure with mmx2
should fix fate failure on freebsd mmx2 client

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