{Object::operator->} will be removed soon.

R=tebbi@chromium.org

Bug: v8:9183, v8:3770
Change-Id: Ifb7754c16055aec41dd30a92e81521a830de4f26
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1624210Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61750}