If an object made it into serialization, it probably deserves to be in
old space when it is deserialized. This will also make off-thread
deserialization simpler, as there is no off-thread new space.

Bug: chromium:1075999
Change-Id: Icabf2f0ae0a3e0205a1094dd0ffe675e69bd1d8e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2184291
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67606}