Add an array of canonical rtts on the isolate. Each wasm instance
copies its rtts from there, based on the type index -> canonical index
mapping in the module.

Bug: v8:7748
Change-Id: I0958686c51ecab15a3215a0da3bee1ad6d543cb3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3548821Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79712}