... in order to avoid expensive computation of cage_base for Code
objects and in order to avoid issues with wrong cage base values
computed from Code objects in external code space.
Drive-by: cage-bas'ify some accessors in JSFunction and Code.

This is a step towards Code-less embedded builtins.

Bug: v8:11880
Change-Id: I95dd8bcd4680e09c7463e1bc7d72dcbf9f2e5c1c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3769831Reviewed-by: Patrick Thier <pthier@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Cr-Commit-Position: refs/heads/main@{#81788}