Use InternalArray in Object.getOwnPropertyNames() implementation

src/array.js

Index: src/array.js
diff --git a/src/array.js b/src/array.js
index 1ec643304b068074cff0171411fba92225444f9b..7cf744bedf29fc9c138b848d8d66d9021cd8afa0 100644
--- a/src/array.js
+++ b/src/array.js
@@ -1553,6 +1553,7 @@ function SetUpArray() {
   // exposed to user code.
   // Adding only the functions that are actually used.
   SetUpLockedPrototype(InternalArray, $Array(), $Array(
+    "concat", getFunction("concat", ArrayConcat),
     "indexOf", getFunction("indexOf", ArrayIndexOf),
     "join", getFunction("join", ArrayJoin),
     "pop", getFunction("pop", ArrayPop),