Vulkan: Add a new garbage type gated by fences. This allows Vulkan EGL objects such as EGL Syncs and EGL Images to give their garbage to the renderer before destroying. BUG=angleproject:2464 Change-Id: I59b8e1080e4292bd0856e59a928750c7e77a372e Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1562522 Commit-Queue: Geoff Lang <geofflang@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>