Vulkan: Use VK_EXT_pipeline_robustness In this change, the global robustBufferAccess feature is disabled. Using this extension, this behavior is enabled for pipelines created for programs built in GL contexts that have robustness enabled. Includes a fix for transform feedback emulation where pausing transform feedback didn't actually stop it from writing output (and overrunning the empty buffer). Until now, the perpetual robustBufferAccess had worked around this. Bug: angleproject:5845 Change-Id: Ib413dff5435e9d1f482bea1d1d0f20c5f09ad8a5 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3872507 Reviewed-by: Charlie Lao <cclao@google.com> Reviewed-by: Yuxin Hu <yuxinhu@google.com> Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>