Add comprehensive memory barrier tests Optimizing glMemoryBarrier can get very tricky. This change adds tests for every glMemoryBarrier bit in different scenarios for a total of about 1500 tests. With the current implementation, there are no syncval errors running these tests. Bug: angleproject:5070 Change-Id: I5358bfeed84f586a67c90ba5ab0fe624db6820b5 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2698288 Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Tim Van Patten <timvp@google.com> Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>