Enable this in Kororo builds to ensure that output isn't dependent on
hash values.
Change-Id: Ib538385b53bebf5260186b14cea396dac15caf6c
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/113980
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>