When introducing LoadImmutable, we missed a couple of places where it
can be used like Load.

Change-Id: If02f6f1ad01d9b68ee757b38689e9f6336a6fb1d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3118545Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Cr-Commit-Position: refs/heads/main@{#76512}