Add support to atomically load (untagged) values from objects to CSA.

Bug: v8:12007
Change-Id: If0c4f20f20e021ace3b1e3a874c0405574d313e1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3627513
Commit-Queue: Patrick Thier <pthier@chromium.org>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Cr-Commit-Position: refs/heads/main@{#80444}