This increases compatibilty with nasm and is also more consistent, e.g. with h264_intrapred.asm and h264_chromamc.asm that already do it that way. Originally committed as revision 25042 to svn://svn.ffmpeg.org/ffmpeg/trunk
issues on Win64. Originally committed as revision 24988 to svn://svn.ffmpeg.org/ffmpeg/trunk