This CL adds const-eval for the `normalize` builtin.
Bug: tint:1581
Change-Id: I6d5ba3e0ba507921137ca90c4caefa9daf88f735
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/111740
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Commit-Queue: Dan Sinclair <dsinclair@chromium.org>