Add Array support for @@species and subclassing

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 19acc7b843a5e97009448c32edd02330dcd0e148..8d0448382b93bbddc003a0187b3efcf688712c1c 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -1346,6 +1346,10 @@ class Object {
   // by ES6 Map and Set.
   bool SameValueZero(Object* other);
 
+  // ES6 section 9.4.2.3 ArraySpeciesCreate (part of it)
+  MUST_USE_RESULT static MaybeHandle<Object> ArraySpeciesConstructor(
+      Isolate* isolate, Handle<Object> originalArray);

[adamk, 2016/01/06 00:10:12]

Nit: original_array

+
   // Tries to convert an object to an array length. Returns true and sets the
   // output parameter if it succeeds.
   inline bool ToArrayLength(uint32_t* index);