We optimize trivial type checks in the function body decoder, i.e.,
ref.as_<type> and ref.is_<type> when invoked on a value that is
statically known to be of typeable as <type>.

Bug: v8:7748
Change-Id: Ieee608a965ba44c4cadd9c7171ed8bdc129fce8b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3447375Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79061}