This reverts commit 3f74ece9.

Reason for revert: build breakage, rebasing issue

Original change's description:
> [wasm-gc] Implement ref.test and ref.cast
> 
> Bug: v8:7748
> Change-Id: If0023edf2f27448c605bd8aa6402bf76c7983a6e
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2277889
> Reviewed-by: Andreas Haas <ahaas@chromium.org>
> Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#68640}

TBR=jkummerow@chromium.org,ahaas@chromium.org

Change-Id: Idd4eee1711aed3c0a9f89a36793738c72a34c783
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:7748
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2278462Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68641}