The tests were written with the assumption that the X_BARRIER_BIT
implied two barriers, write->X and X->write. However, they only imply
write->X, with the exception of SHADER_IMAGE_ACCESS_BARRIER_BIT and
SHADER_STORAGE_BARRIER_BIT which handle X->write for images and buffers
respectively.
Bug: angleproject:5070
Change-Id: Ic9bfac997d0663b70f1d40baca6c111a4dc300c9
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2705701
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Tim Van Patten <timvp@google.com>
