BUG=libyuv:703
TEST=compile and disassemble.  see registers used not stack.
R=wangcheng@google.com

Change-Id: Iaa07ee5d0c35252994491bb2868276e161149efd
Reviewed-on: https://chromium-review.googlesource.com/500427
Commit-Queue: Frank Barchard <fbarchard@google.com>
Reviewed-by: Cheng Wang <wangcheng@google.com>