Pretenure code generation corner case with new space COW arrays.

src/heap.h

Index: src/heap.h
diff --git a/src/heap.h b/src/heap.h
index 304e1f86f0dffb70cc26f5d2eeab285cb1ae4a2a..ad56d70fc78ae1823d1a7362a55dd044be6fb7eb 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -979,6 +979,10 @@ class Heap {
   // Failure::RetryAfterGC(requested_bytes, space) if the allocation failed.
   MUST_USE_RESULT inline MaybeObject* CopyFixedArray(FixedArray* src);
 
+  // Make a copy of src and return it. Returns
+  // Failure::RetryAfterGC(requested_bytes, space) if the allocation failed.
+  MUST_USE_RESULT MaybeObject* CopyAndTenureFixedCOWArray(FixedArray* src);
+
   // Make a copy of src, set the map, and return the copy. Returns
   // Failure::RetryAfterGC(requested_bytes, space) if the allocation failed.
   MUST_USE_RESULT MaybeObject* CopyFixedArrayWithMap(FixedArray* src, Map* map);