[heap] Move RecomputeLimits into safepoint

Recompute heap limits while all threads are still stopped. Otherwise
setting the limits races with concurrent background threads performing
allocations.

Bug: v8:10315
Change-Id: I17e711b960e1fde05adb4f4b794f813b94190ef1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2157375
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67280}

src/heap/heap.cc

@@ -2097,6 +2097,9 @@ bool Heap::PerformGarbageCollection(
     Verify();
   }
 #endif
+
+  RecomputeLimits(collector);
+
   if (FLAG_local_heaps) safepoint()->End();
 
   {
@@ -2117,8 +2120,6 @@ bool Heap::PerformGarbageCollection(
   // Update relocatables.
   Relocatable::PostGarbageCollectionProcessing(isolate_);
 
-  RecomputeLimits(collector);
-
   {
     GCCallbacksScope scope(this);
     if (scope.CheckReenter()) {