Resize() may be used to adjust additional trailing bytes of an object.
It is up to the embedder to ensure correctness in case of shrinking.

Bug: chromium:1056170
Change-Id: I954df6c7440b77275cd62e4b802e8f5d39c06f9d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2739652
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73277}