This is moving needed stuff out of #if V8_ENABLE_WEBASSEMBLY.

Everything related to guards is still behind V8_ENABLE_WEBASSEMBLY,
since RAB / GSAB don't use guards.

Bug: v8:11111
Change-Id: I9b9fd0dbdcdc1f3c70d6e4f5eb1c70d1bab98e68
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2880221Reviewed-by: Clemens Backes <clemensb@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74476}