This is a reland of commit ee89a269

Original change's description:
> [wasm-gc] Add extern.externalize
>
> This adds `extern.externalize(ref null any): ref null extern` to wasm
> which packs wasm objects into JS objects if the js-interop flag is not set.
> This is the counterpart to extern.internalize introduced in
> 50ec8a11.
>
> Bug: v8:7748
> Change-Id: I67b8fe6d70b9f526ff6c43b0a4d7861c7ff5dad0
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3825879
> Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
> Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
> Commit-Queue: Matthias Liedtke <mliedtke@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#82492}

Bug: v8:7748
Change-Id: Ie13cfd6464006dcadc2a53f2dbf77f76ab185504
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3829940Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Auto-Submit: Matthias Liedtke <mliedtke@chromium.org>
Commit-Queue: Nico Hartmann <nicohartmann@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82551}