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/+/2698288Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Tim Van Patten <timvp@google.com>
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>