Support Smi->Double->HeapObject transitions in constructed Arrays.

src/factory.h

Index: src/factory.h
diff --git a/src/factory.h b/src/factory.h
index 0f028e5c5968e77a046d65a508fd5cfe10583468..9b31536ecfdf6336ac736a8906144f8fcfb7e7c9 100644
--- a/src/factory.h
+++ b/src/factory.h
@@ -259,12 +259,15 @@ class Factory {
                              PretenureFlag pretenure = NOT_TENURED);
 
   Handle<JSArray> NewJSArrayWithElements(
-      Handle<FixedArray> elements,
+      Handle<FixedArrayBase> elements,
       PretenureFlag pretenure = NOT_TENURED);
 
-  void SetContent(Handle<JSArray> array, Handle<FixedArray> elements);
+  void SetContent(Handle<JSArray> array, Handle<FixedArrayBase> elements);
 
-  void EnsureCanContainNonSmiElements(Handle<JSArray> array);
+  void EnsureCanContainHeapObjectElements(Handle<JSArray> array);
+  void EnsureCanContainElements(Handle<JSArray> array,
+                                Handle<FixedArrayBase> elements,
+                                EnsureElementsMode mode);
 
   Handle<JSProxy> NewJSProxy(Handle<Object> handler, Handle<Object> prototype);