This is done by making sure that LSB of the cage-base is 1. This way we
know that on compression normal pointers after the shift will have the
MSB set to 1.

Bug: chromium:1325007
Change-Id: I8699aaa464f1a8c18d2092f5eb474266fb409fcb
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3688399
Commit-Queue: Anton Bikineev <bikineev@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/main@{#81039}