Crashkeys are static and non-refcounted, so when one thread clears
a crashkey, it affects all other threads. This means, we cannot set
them in parallel running jobs such as ScavengePage. This change moves
the crashkey about heap collection up the stack into the main thread.

Change-Id: I28f16eaadd9b122c06a68d1d4207f27319994509
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1874384Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Irina Yatsenko <irinayat@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#64523}