expect avx2 compiler support means one of the avx2 functions exists. BUG=none TESTED=try bots R=bcornell@google.com
expect avx2 compiler support means one of the avx2 functions exists.
BUG=none
TESTED=try bots
R=bcornell@google.com

Review URL: https://webrtc-codereview.appspot.com/22299004

git-svn-id: a51711482b6ba0e1d1ab095578a045eeae45ac9a@1076 16f28f9a-4ce2-e073-06de-1de4eb20be90

granalberto/libyuv,granalberto/libyuv,granalberto/libyuv,rig-project/libyuv,archos-sa/libyuv-avp,granalberto/libyuv,rig-project/libyuv,rig-project/libyuv,archos-sa/libyuv-avp,archos-sa/libyuv-avp