Vulkan: Command graph linearization (Step 2). ES 2.0 is feature complete. Passes all of the angle_end2end_tests with the new linear command recording method. Also runs the T-Rex benchmark without any obvious glitches. Likely has issues with creating too many RenderPasses. ES3 is mostly untouched. Bug: angleproject:4029 Change-Id: Ic5acf3d768495fbffd07b07bf0a6f2b5787c51f8 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2012900 Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Jamie Madill <jmadill@chromium.org>