This change enables direct SPIR-V generation for compute shaders and enables a few tests. A handful of built-in functions are translated to support said tests. Bug: angleproject:4889 Change-Id: I8fd6dc50ff31559a738ba680a993fb197e29fcf9 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2939330 Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Tim Van Patten <timvp@google.com>
