Pull the HLSL transformation out to a standalone transform that can be
used by both HLSL and MSL.
The new E2E tests do not yet pass for MSL because they produce array
assignments, which will be addressed in the next patch.
Fixed: tint:826
Change-Id: Idc27c81ad45e3d4ab96d82663927d2fc1384618e
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/52842
Auto-Submit: James Price <jrprice@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
42220ba1b2