Added ES5 15.2.3.2 Object.getPrototypeOf.

test/mjsunit/get-prototype-of.js

Index: test/mjsunit/get-prototype-of.js
===================================================================
--- test/mjsunit/get-prototype-of.js	(revision 0)
+++ test/mjsunit/get-prototype-of.js	(revision 0)
@@ -0,0 +1,68 @@
+// Copyright 2010 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+function TryGetPrototypeOfNonObject(x) {
+  var caught = 0;
+  try {
+      Object.getPrototypeOf(x);
+  } catch (e) {
+    caught = e;
+  }
+
+  assertTrue(caught instanceof TypeError);
+};
+
+function GetPrototypeOfObject(x) {
+  assertDoesNotThrow(Object.getPrototypeOf(x));
+  assertNotNull(Object.getPrototypeOf(x));
+  assertEquals(Object.getPrototypeOf(x), x.__proto__);
+}
+
+function F(){};
+
+// Non object
+var x = 10;
+
+// Object
+var y = new F();
+
+// Make sure that TypeError exceptions are thrown when non-objects are passed
+// as argument
+TryGetPrototypeOfNonObject(0);
+TryGetPrototypeOfNonObject(null);
+TryGetPrototypeOfNonObject('Testing');
+TryGetPrototypeOfNonObject(x);
+
+// Make sure the real objects have this method and that it returns the
+// actual prototype object. Also test for Functions and RegExp.
+GetPrototypeOfObject(this);
+GetPrototypeOfObject(y);
+GetPrototypeOfObject({x:5});
+GetPrototypeOfObject(F);
+GetPrototypeOfObject(RegExp);
+