BUG=libyuv:701
TEST=built and disassembled for aarch64
R=kjellander@chromium.org

Change-Id: I7712b1c7934e5dfb55fda1fa7c8405c32d6964ce
Reviewed-on: https://chromium-review.googlesource.com/495327Reviewed-by: Henrik Kjellander <kjellander@chromium.org>
Reviewed-by: Cheng Wang <wangcheng@google.com>