It could happen that a background thread expands the heap by one page,
but by the time the thread tries to allocate on it the space is already
used by other background threads. If this happens three times in a row,
V8 would crash with an OOM error. This CL prevents such situations by
always allocating the object immediately at area_start().

Bug: v8:10315
Change-Id: I6390c84e742bf4105e70e930c21557ff1f4d952d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2743881Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73305}