Only shrink new space when we are not in the process of obtaining pretenuring feedback.

src/heap/heap.h

Index: src/heap/heap.h
diff --git a/src/heap/heap.h b/src/heap/heap.h
index a580695eb471af82992d3fea81f9127528d11bde..ac4d3b37baa6e2aa225edefa4f266e8ff25321e3 100644
--- a/src/heap/heap.h
+++ b/src/heap/heap.h
@@ -1862,7 +1862,7 @@ class Heap {
   // space evacuation. Note that between feedback collection and calling this
   // method object in old space must not move.
   // Right now we only process pretenuring feedback in high promotion mode.
-  void ProcessPretenuringFeedback();
+  bool ProcessPretenuringFeedback();
 
   // Checks whether a global GC is necessary
   GarbageCollector SelectGarbageCollector(AllocationSpace space,