[heap] Reset time_to_collection_scope_ on TearDown

Scope might still be in progress and needs to be closed when starting
tear down. There will be no GC after starting tear down anymore.

Bug: v8:11022, v8:10315
Change-Id: I50ea02b13b84ef4fbbc08985ca9e25e0b0ec856d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2470572Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70507}

src/heap/collection-barrier.cc

@@ -17,6 +17,7 @@ void CollectionBarrier::ResumeThreadsAwaitingCollection() {
 
 void CollectionBarrier::ShutdownRequested() {
   base::MutexGuard guard(&mutex_);
+  time_to_collection_scope_.reset();
   state_.store(RequestState::kShutdown);
   cond_.NotifyAll();
 }