[heap] Use atomic marking operations in incremental marking if

src/heap/incremental-marking.h

Index: src/heap/incremental-marking.h
diff --git a/src/heap/incremental-marking.h b/src/heap/incremental-marking.h
index 14dce2c867e14fb14ebeaf503445e8f2923cce3f..7945e60b3ce40d8c87b055a6c3d9eeeb24c5663f 100644
--- a/src/heap/incremental-marking.h
+++ b/src/heap/incremental-marking.h
@@ -182,6 +182,12 @@ class V8_EXPORT_PRIVATE IncrementalMarking {
   static const intptr_t kActivationThreshold = 0;
 #endif
 
+#ifdef V8_CONCURRENT_MARKING
+  static const MarkBit::AccessMode kAtomicity = MarkBit::AccessMode::ATOMIC;
+#else
+  static const MarkBit::AccessMode kAtomicity = MarkBit::AccessMode::NON_ATOMIC;
+#endif
+
   void FinalizeSweeping();
 
   size_t Step(size_t bytes_to_process, CompletionAction action,