Fix use of proxies as f.prototype properties.

test/mjsunit/harmony/proxies.js

 // Copyright 2011 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 2239 matching lines @@
 
 TestIsEnumerableThrow(Proxy.create({
   get: function(pr, pk) { throw "myexn" }
 }))
 
 TestIsEnumerableThrow(Proxy.create({
   get: function(pr, pk) {
     return function(k) { throw "myexn" }
   }
 }))
+
+
+
+// Constructor functions with proxy prototypes.
+
+function TestConstructorWithProxyPrototype() {
+  TestWithProxies(TestConstructorWithProxyPrototype2, {})
+}
+
+function TestConstructorWithProxyPrototype2(create, handler) {
+  function C() {};
+  C.prototype = create(handler);
+
+  var o = new C;
+  assertSame(C.prototype, o.__proto__);
+  assertSame(C.prototype, Object.getPrototypeOf(o));
+}
+
+TestConstructorWithProxyPrototype();