Jitless mode does not allocate executable memory, so we can avoid reserving
memory in such configurations.

Bug: v8:10033
Change-Id: Ie6a943084e3bade85848e3219cb4d8779ed34830
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1981505
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66388}