These suffixes existed because the GN build errored when there were two files sets with the same name (ast + sem).
This is no longer required as the GN build splits these into two separate targets.
Change-Id: Ib451da33a5f4aa5c867cb99419dd252766dc3daa
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/88308
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: James Price <jrprice@google.com>
Reviewed-by: Dan Sinclair <dsinclair@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>
Ben Clayton