Removes validation preventing integer formats from being cleared to
>2^24. Adds a test that clears to the largest values for UINT32 and
SINT32 formats.
Bug: dawn:537
Change-Id: I8aabd36608138725c8ddbbedd50192c0978da99c
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/30300
Reviewed-by: Austin Eng <enga@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Brandon Jones <brandon1.jones@intel.com>