Set mCurrentGraphicsPipeline = nullptr when the pipeline layout is recreated if immutable samplers are used to prevent a use-after-free. For a fuller discussion on why this is necessary, see: Vulkan: clear mCurrentGraphicsPipeline during invalidate | https://chromium-review.googlesource.com/c/angle/angle/+/2647746 Bug: b/178424566 Bug: angleproject:5624 Change-Id: I70679bda85cd587dbd8893a4576ee5d33aee2b70 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2683041 Commit-Queue: Tim Van Patten <timvp@google.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>
