The texture_storage_3d overload should allow for unsigned coordinates.
Change-Id: I6278571fb9dc7bba644a4ba88cce6b8bd7c790bf
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/122521
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: James Price <jrprice@google.com>