Port e5524920

Original Commit Message:

    This might or might not give clang-tidy a hint that the reported case
    (see issue) cannot happen. It might also generate slightly better code
    by giving hints to the compiler.
    Note that V8_ASSUME is actually a DCHECK in DEBUG builds, so we do not
    loose any checks here.

    Some DCHECKs were removed because they are redundant
    (RegisterBase::code() assumes to be only called on valid registers).

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

Change-Id: I653d398eb4b6b10fa769de62a9900edda95dd5db
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3820583
Commit-Queue: Milad Farazmand <mfarazma@redhat.com>
Reviewed-by: Junliang Yan <junyan@redhat.com>
Cr-Commit-Position: refs/heads/main@{#82318}