Also changes enums to use the concept of "limit class" from the WebGPU
specification.
Fixed: dawn:1242
Change-Id: I328ce98c2eaaf3f4b7ff1c253ee5f3db5a2980f5
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/84762
Reviewed-by: Austin Eng <enga@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>