Add new semantics + compat fallback to Intl constructor

test/intl/assert.js

 // Copyright 2013 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
@@ skipping 155 matching lines @@
   }
 }
 
 
 /**
  * Throws if obj is not of given type.
  */
 function assertInstanceof(obj, type) {
   if (!(obj instanceof type)) {
     var actualTypeName = null;
-    var actualConstructor = Object.prototypeOf(obj).constructor;
+    var actualConstructor = Object.getPrototypeOf(obj).constructor;
     if (typeof actualConstructor == "function") {
       actualTypeName = actualConstructor.name || String(actualConstructor);
     }
     throw new Error('Object <' + obj + '> is not an instance of <' +
-         (type.name || type) + '>' +
-         (actualTypeName ? ' but of < ' + actualTypeName + '>' : ''));
+                    (type.name || type) + '>' +
+                    (actualTypeName ? ' but of < ' + actualTypeName + '>' : ''));
   }
 }