- Adds a method to tell V8 that the process is cross-origin-isolated
  under COOP+COEP. In this case, SharedArrayBuffer can be enabled.

Bug: chromium:923807
Change-Id: I729093665a50d2b3667c028e05b42d21d76b12d3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2502448Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Bill Budge <bbudge@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70805}