libyuv updates for better code generation on OSX clang for scale
BUG=478
TEST=build libyuv and disassemble scale.o with otool -tV.  Should use registers for C loops, not stack.
Review URL: https://webrtc-codereview.appspot.com/550005

git-svn-id: http://webrtc.googlecode.com/svn/trunk@2155 4adac7df-926f-26a2-2b94-8c16560cd09d
1 file changed