A hypothetical case discussed in the WG call, which I wasn't entirely sure was going to work. It does.
Change-Id: I855f1e02af2fe62214e3fb964f6937e3d88016eb
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/59021
Auto-Submit: Ben Clayton <bclayton@google.com>
Reviewed-by: James Price <jrprice@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>