Vulkan: Implement masked color clear with depth. This fixes an edge case when the app clears both color and depth at the same time when a color mask is set. It also handles stencil clear, but does not handle stencil masks. Includes test suppressions for a few platforms that may have driver bugs. Bug: angleproject:2455 Bug: angleproject:2547 Bug: angleproject:2548 Change-Id: I5ac0a461a075328e5fc4e5e262c4d21f68f93434 Reviewed-on: https://chromium-review.googlesource.com/1052072 Reviewed-by: Geoff Lang <geofflang@chromium.org> Reviewed-by: Luc Ferron <lucferron@chromium.org> Commit-Queue: Jamie Madill <jmadill@chromium.org>