Run SimulateFullSpace in safepoint. Needed for FreeLinearAllocationArea
which would race with concurrent allocation.

Bug: v8:10315
Change-Id: If0c3c4e20edea1b05cc1a3e1a3e37fc29254a196
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2354812Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69395}