V8's write barrier doesn't use a store buffer anymore but inserts
directly into the remembered set. However, there were still some
comments/method definitions left.

Bug: v8:9454
Change-Id: Ic3bc3394750f1d4989027e07dbc9201c3f484ccd
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3270536Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77814}