We are using VK_PIPELINE_STAGE_ALL_COMMANDS_BIT for
mGlobalMemoryBarrierStages, which is used for both src and dst. This
will cause a full pipeline stall whenever a buffer object introduces a
barrier. This CL will let the caller pass in the specific stage it
will be used for, allowing us to track write and read stage dependencies
separately and request the corresponding barriers.

Bug: b/155122200
Change-Id: I8b8bd291a03b77d07cfbcbe7c3cda2d3771588b9
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2169014
Commit-Queue: Charlie Lao <cclao@google.com>
Reviewed-by: Tim Van Patten <timvp@google.com>
Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>