Complete ptest and add vptest
Add Pcmpeqb, Pcmpeqw, Ptest macro

Change-Id: I060aa5228d50f2dca7ed3e24324a08c04ec1a028
Reviewed-on: https://chromium-review.googlesource.com/1013236Reviewed-by: Bill Budge <bbudge@chromium.org>
Commit-Queue: Jing Bao <jing.bao@intel.com>
Cr-Commit-Position: refs/heads/master@{#52687}