Graceful degredation for SkOpts_hsw.

__AVX2__ will not be defined if you omit -mavx2.  Android does this
intentionally for x86 builds.  (No mobile CPU supports AVX2 AFAIK.)

This should fix the Android roll.

Change-Id: Ib94c862641abc11fbb46863afc53bcc049f362ad
Reviewed-on: https://skia-review.googlesource.com/7633
Commit-Queue: Mike Klein <mtklein@chromium.org>
Reviewed-by: Mike Klein <mtklein@chromium.org>
Reviewed-by: Matt Sarett <msarett@google.com>
1 file changed