According to the latest changes in wasm-gc, externref will be renamed
to anyref, and will be assigned as the top of the reference type
hierarchy. Since in the current wasm type system funcref is not a
subtype of anyref, subtyping is now dependent on whether wasm-gc is
enabled.

Bug: v8:7748
Change-Id: I0c0ae3dd5523e624d4490ca33d1fba4c2ae59393
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3468345Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79322}