... to ensure that it'll not be triggered for Code objects which
are known to never be in new space.

This removes the need for having custom implementation of setters with
Code values - existing [CONDITIONAL_]WRITE_BARRIER macros will work
just fine.

Bug: v8:11879, v8:11880
Change-Id: I7ed70e51f9459040086dd4c67e61b11617dbdc24
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2964812Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75166}