This remodels the tier-up checks on loop back edges to avoid
modifying the cache state by taking temp registers passed in
from the caller, and not causing the instance to get cached.

Additionally, this introduces FreezeCacheState scopes, which
allow us to enforce that certain ranges don't cause any cache
modifications. Conditional jumps require such a scope to be
around, which should help ensure that we don't forget to add
them to any future code we write.

Drive-by cleanup: drop {pinned} lists from a few Load helper
functions. They don't allocate registers (and shouldn't), so
they don't need to know about pinned registers.

Fixed: chromium:1339321
Change-Id: I1c7660418a85259e96c5e0dcfeaf12dab2114e8c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3724787Reviewed-by: Manos Koukoutos <manoskouk@chromium.org>
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/main@{#81411}