Per issue 4889, dependency to glslang is being dropped.  This change
generates the unresolve UtilsVk shader directly in SPIR-V.

This shader is trivial and contains repeating patterns per attachment.
As a result, generating its SPIR-V is exceptionally simple.  The SPIR-V
in this change is first generated by glslang validator and is then
adapted for autogeneration.

See comments in the code for details.

Bug: angleproject:4889
Change-Id: I48dd77ae04e1035c05a8aef7bf2f161e105ae2a4
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2407179
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Tim Van Patten <timvp@google.com>