ES6: Error functions should extend Error

test/mjsunit/es6/error-functions-prototypes.js

Index: test/mjsunit/es6/error-functions-prototypes.js
diff --git a/test/mjsunit/es6/error-functions-prototypes.js b/test/mjsunit/es6/error-functions-prototypes.js
new file mode 100644
index 0000000000000000000000000000000000000000..2f5efa0543515bc7f528b926e92e21d758cc49af
--- /dev/null
+++ b/test/mjsunit/es6/error-functions-prototypes.js
@@ -0,0 +1,17 @@
+// Copyright 2015 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.
+
+
+function assertPrototypeOf(expected, func) {
+  assertEquals(expected, Object.getPrototypeOf(func));
+}
+
+
+assertPrototypeOf(Function.prototype, Error);
+assertPrototypeOf(Error, TypeError);
+assertPrototypeOf(Error, RangeError);
+assertPrototypeOf(Error, SyntaxError);
+assertPrototypeOf(Error, ReferenceError);
+assertPrototypeOf(Error, EvalError);
+assertPrototypeOf(Error, URIError);