Comments on this reservation indicate it may hold either only code pages or code
and data pages if pointer compression is enabled.  But in fact it only holds the
reservation for code pages.

Change-Id: Ic007fcadf881153b69dce51db561777cc52685bf
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2091465Reviewed-by: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Pierre Langlois <pierre.langlois@arm.com>
Cr-Commit-Position: refs/heads/master@{#66612}