Mostly in comments, again, not much to be said...
One case of UNREACHABLE with return.

Bug: v8:12425
Change-Id: I295db355c4794e4205b9b70ebbf51e019ec14060
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3695265Reviewed-by: Marja Hölttä <marja@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Nikolaos Papaspyrou <nikolaos@chromium.org>
Cr-Commit-Position: refs/heads/main@{#81240}