The mechanisms don't interact well. NodeObserver assumes synchronous
compilation that finishes within the ObserverNodeScope. One could
ensure all relevant lifetimes (of the NodeObserver itself, and all
captured pointers) exceed that of all spawned jobs, but simply
disabling the additional concurrent job in these cases is a
pragmatic fix for now.

Bug: v8:11658
Change-Id: I41b2f96f0166b661cf0cca94ef809ca99475e420
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2833915
Auto-Submit: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74022}