Add `transform::DecomposeStridedMatrix`, which replaces matrix members of storage or uniform buffer structures, that have a [[stride]] decoration, into an array
of N column vectors.
This is required to correctly handle `mat2x2` matrices in UBOs, as std140 rules will expect a default stride of 16 bytes, when in WGSL the default structure layout expects a stride of 8 bytes.
Bug: tint:1047
Change-Id: If5ca3c6ec087bbc1ac31a8d9a657b99bf34042a4
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/59840
Reviewed-by: David Neto <dneto@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>