The utility type is independent of V8 and useful for cppgc as well.
Move to base/ to allow reusing.

Change-Id: I9de9b4a87bb113fb4c2232d90253afb0f38faa68
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3497336Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79346}