Due to the consistent overhead of snapshot checksum verification
we ideally want to avoid it all-together. However there are still enough
devices out there that suffer from corrupted snapshots that might
cause hard to debug heap corruptions.

This CL exposes the calculated (dummy value for now) and the expected
snapshot checksum as a crash key, so it can be easily consulted during
investigation.

Note: The calculated crash key contains 0x0 for now as a dummy value. We
will come up with a strategy later-on to limit the overhead of
calculating the checksum.

Bug: v8:12195
Change-Id: I6da6d74c035cb6f9b0edae212a36e6c41c048a5b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3605813Reviewed-by: Jakob Linke <jgruber@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/main@{#80325}