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 f99bb51617e1cf8145802cc81fe70a19326cbdc9..73c990a8988148dc98ed7d27e57de9eab79b1727 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);