Support full deoptimization during GC via stack guard.

src/heap.h

Index: src/heap.h
diff --git a/src/heap.h b/src/heap.h
index 9e758aaa06441317d2952d32feb9eddb2a34de6f..46c75fe141efb7789d6eebc52508543952c2dd13 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -1498,6 +1498,12 @@ class Heap {
   MUST_USE_RESULT MaybeObject* AllocateRawFixedArray(int length,
                                                      PretenureFlag pretenure);
 
+  // Predicate that governs global pre-tenuring decisions based on observed
+  // promotion rates of previous collections.
+  inline bool ShouldGloballyPretenure() {
+    return new_space_high_promotion_mode_active_;
+  }
+
   inline intptr_t PromotedTotalSize() {
     return PromotedSpaceSizeOfObjects() + PromotedExternalMemorySize();
   }