Remove gl_PerVertex-related suppression Bug: angleproject:5579 Change-Id: I532bc2628f8d69aa429c73dc5613ccb5375109a5 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3437411 Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com> Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>