We can use existing macros to define this getter/setter rather than hand
writing it -- as a side effect this ends up defining an Isolate overload
of the getter which was otherwise missing.

Bug: v8:10506
Change-Id: I0bc5a3082b5ed0416c8099a94e7d2e32a2bd363f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2199350
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Auto-Submit: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67798}