A general code cleanup
Change-Id: Ib251ca2d4b71f75736bdba8b4255965593a76c31
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/48680
Auto-Submit: Ben Clayton <bclayton@google.com>
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Reviewed-by: James Price <jrprice@google.com>
Commit-Queue: Antonio Maiorano <amaiorano@google.com>