The zone-allocated objects, the destructor is never called. Such
objects must therefore never contain members that themselves have
non-trivial destructors, e.g. std containers.

Fix occurrences of this antipattern in Maglev.

Bug: v8:7700
Change-Id: I6892cf5203bb6e842397fd4292918b18134f97cc
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3822672
Auto-Submit: Jakob Linke <jgruber@chromium.org>
Reviewed-by: Victor Gomes <victorgomes@chromium.org>
Commit-Queue: Victor Gomes <victorgomes@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82358}