Port 781a5b5a

Original Commit Message:

    Many platform-dependent LiftoffAssembler methods do not use all
    parameters. Comment out the name of unused ones, to make it easier to
    see which implementation uses which parameters.

    Also, remove {is_load_mem} from arm's {LoadInternal}, because it is
    unused there.

R=clemensb@chromium.org, joransiu@ca.ibm.com, junyan@redhat.com, midawson@redhat.com
BUG=
LOG=N

Change-Id: I861df687e373ed7dd302fc5e2e1299f09f899166
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3792177
Commit-Queue: Milad Farazmand <mfarazma@redhat.com>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82084}