To match the spec.
Also add a bunch of missing texture test cases to
src/tint/ast/builtin_texture_helper_test.cc. Fix all the tests that were
broken because these were not being exercised.
Fixed: tint:1526
Change-Id: I207b51d307bbdc054b595e0e0e0fd3330607e171
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/106681
Reviewed-by: Dan Sinclair <dsinclair@chromium.org>
Auto-Submit: Ben Clayton <bclayton@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>