When this is enabled, v8 reserves a large region of virtual address
space during initialization, at the start of which it will place its 4GB
pointer compression cage. The remainder of the cage is used to store
ArrayBuffer backing stores and WASM memory buffers. This will later
allow referencing these buffers from inside V8 through offsets from the
cage base rather than through raw pointers.

Bug: chromium:1218005
Change-Id: I300094b07f64985217104b14c320cc019f8438af
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3010195Reviewed-by: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Samuel Groß <saelo@google.com>
Cr-Commit-Position: refs/heads/master@{#76234}