We can hardcode the result and to make sure we are using the correct
offset, we now have a static_assert.

Change-Id: Ic04ce9f8e46847504d3d0a5921f55cb750f7f3ad
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2831473
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74044}