... and add regression test for contextual stores to JSGlobalObject
with interceptor in the prototype chain.

Bug: chromium:1216437
Change-Id: Ibd344288c6327b35f3276f59517995d591acb967
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2944895
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75038}