Vulkan: Implement stencil test support All the fragment_ops.depth and the fragment_ops.depth tests in dEQP are now working, but not the fragment_ops.depth_stencil. Still debugging these separately and will come up with a fix for them in another commit. Bug: angleproject:2443 Change-Id: I84c3a22f612fb6dcf30598434f96c2100fd29f9c Reviewed-on: https://chromium-review.googlesource.com/993654 Commit-Queue: Luc Ferron <lucferron@chromium.org> Reviewed-by: Corentin Wallez <cwallez@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>