Vulkan: Prune superseded staged updates in a texture Add support for pruning superseded staged updates from a client buffer to the texture. If the staged update count or the cumulative staged updates' size exceeds a threshold we check for superseded updates and prune the list. Bug: angleproject:4691 Bug: angleproject:7389 Test: Texture2DTest.InterleavedSupersedingTextureUpdates* Texture2DTest.ManySupersedingTextureUpdates* Change-Id: I4b84f13fa20004a3dc68baa552a0af656d92c0a1 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3691092 Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Commit-Queue: mohan maiya <m.maiya@samsung.com>