The DCHECK must use atomic accessors as well.

Change-Id: I94983c1e38bc9d436f1577509788fc21e3d4e374
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3300143
Auto-Submit: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78077}