This is cruft left over from file name collisions between ast / sem,
which has been resolved by splitting the build targets.
Change-Id: I0d65ffe97fed7095b37cc91a506dd05a20cda76a
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/106222
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: Dan Sinclair <dsinclair@chromium.org>