Implement ES6 Array.of()

test/mjsunit/es6/array-of-length-setter-2.js

+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Based on: https://hg.mozilla.org/mozilla-central/file/d0c3168c3c47/js/src/jit-test/tests/collections/Array-of-length-setter-2.js
+
+// Flags: --harmony-arrays
+
+
+// Array.of does a strict assignment to the new object's .length.
+
+// The assignment is strict even if the code we're calling from is not strict.
+
+function Empty() {}
+Empty.of = Array.of;
+Object.defineProperty(Empty.prototype, "length", {get: function() { return 0; }});
+
+var nothing = new Empty;
+nothing.length = 2;  // no exception; this is not a strict mode assignment