The latest wasm-gc spec introduces classification functions
{ref.as, ref.is, br_on}_{func, data, i31}, to cast values typed as
anyref and eqref.

Bug: v8:7748
Change-Id: I39c288e4a4c96466e64e490f164ccc76b00011ee
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2655506
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72434}