This is required by the MVP spec. In the future, it might be possible
to pass values for any immutable fields.

Bug: v8:7748
Change-Id: Ie7705b48e9d6ebb87d5e1b0a2a10556302395db6
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3793383Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82072}