- Change definition to macro-style to be able to assert that masks/tags
  are correct.
- Split definition of shared/non-shared tags.
- Use bit 62 (for now) to indicate tags are shared.

Bug: v8:10391
Change-Id: Ia3ad6294cf5e6fd0c4dc2a328f976f295da762f5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3726009Reviewed-by: Samuel Groß <saelo@chromium.org>
Commit-Queue: Patrick Thier <pthier@chromium.org>
Cr-Commit-Position: refs/heads/main@{#81400}