Vulkan: Support texture buffers Texture buffers are placed in the same descriptor set with the rest of the textures. However, the different code paths that handle textures have special cases for texture buffers as they create a different descriptor type (texel buffer instead of combined image sampler). Image view serials are used to track the buffer view serials as well so the texture descriptor cache can handle texture buffers as well. This CL is missing storage texel buffer support. Bug: angleproject:3573 Change-Id: Iff80ca22ff9b9957a0c9a3c7aaada1fa54b24ec8 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2532653 Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Tim Van Patten <timvp@google.com>