Fix instanceof a function proxy.

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 1419 matching lines @@
 TestHasOwnThrow(Proxy.create({
   get: function(pr, pk) {
     return function(k) { throw "myexn" }
   }
 }))
 
 
 
 // Instanceof (instanceof)
 
-function TestInstanceof() {
+function TestProxyInstanceof() {
   var o1 = {}
   var p1 = Proxy.create({})
   var p2 = Proxy.create({}, o1)
   var p3 = Proxy.create({}, p2)
   var o2 = Object.create(p2)
 
   var f0 = function() {}
   f0.prototype = o1
   var f1 = function() {}
   f1.prototype = p1
@@ skipping 25 matching lines @@
   assertTrue(o2 instanceof Object)
   assertTrue(o2 instanceof f0)
   assertFalse(o2 instanceof f1)
   assertTrue(o2 instanceof f2)
   assertFalse(o2 instanceof f3)
 
   var f = Proxy.createFunction({}, function() {})
   assertTrue(f instanceof Function)
 }
 
-TestInstanceof()
+TestProxyInstanceof()
+
+
+function TestInstanceofProxy() {
+  var o0 = Object.create(null)
+  var o1 = {}
+  var o2 = Object.create(o0)
+  var o3 = Object.create(o1)
+  var o4 = Object.create(o2)
+  var o5 = Object.create(o3)
+
+  function handler(o) { return {get: function() { return o } } }
+  var f0 = Proxy.createFunction(handler(o0), function() {})
+  var f1 = Proxy.createFunction(handler(o1), function() {})
+  var f2 = Proxy.createFunction(handler(o2), function() {})
+  var f3 = Proxy.createFunction(handler(o3), function() {})
+  var f4 = Proxy.createFunction(handler(o4), function() {})
+  var f5 = Proxy.createFunction(handler(o4), function() {})
+
+  assertFalse(null instanceof f0)
+  assertFalse(o0 instanceof f0)
+  assertFalse(o0 instanceof f1)
+  assertFalse(o0 instanceof f2)
+  assertFalse(o0 instanceof f3)
+  assertFalse(o0 instanceof f4)
+  assertFalse(o0 instanceof f5)
+  assertFalse(o1 instanceof f0)
+  assertFalse(o1 instanceof f1)
+  assertFalse(o1 instanceof f2)
+  assertFalse(o1 instanceof f3)
+  assertFalse(o1 instanceof f4)
+  assertFalse(o1 instanceof f5)
+  assertTrue(o2 instanceof f0)
+  assertFalse(o2 instanceof f1)
+  assertFalse(o2 instanceof f2)
+  assertFalse(o2 instanceof f3)
+  assertFalse(o2 instanceof f4)
+  assertFalse(o2 instanceof f5)
+  assertFalse(o3 instanceof f0)
+  assertTrue(o3 instanceof f1)
+  assertFalse(o3 instanceof f2)
+  assertFalse(o3 instanceof f3)
+  assertFalse(o3 instanceof f4)
+  assertFalse(o3 instanceof f5)
+  assertTrue(o4 instanceof f0)
+  assertFalse(o4 instanceof f1)
+  assertTrue(o4 instanceof f2)
+  assertFalse(o4 instanceof f3)
+  assertFalse(o4 instanceof f4)
+  assertFalse(o4 instanceof f5)
+  assertFalse(o5 instanceof f0)
+  assertTrue(o5 instanceof f1)
+  assertFalse(o5 instanceof f2)
+  assertTrue(o5 instanceof f3)
+  assertFalse(o5 instanceof f4)
+  assertFalse(o5 instanceof f5)
+
+  var f = Proxy.createFunction({}, function() {})
+  var ff = Proxy.createFunction(handler(Function), function() {})
+  assertTrue(f instanceof Function)
+  assertFalse(f instanceof ff)
+}
+
+TestInstanceofProxy()
 
 
 
 // Prototype (Object.getPrototypeOf, Object.prototype.isPrototypeOf).
 
 function TestPrototype() {
   var o1 = {}
   var p1 = Proxy.create({})
   var p2 = Proxy.create({}, o1)
   var p3 = Proxy.create({}, p2)
@@ skipping 690 matching lines @@
 
 TestIsEnumerableThrow(Proxy.create({
   get: function(pr, pk) { throw "myexn" }
 }))
 
 TestIsEnumerableThrow(Proxy.create({
   get: function(pr, pk) {
     return function(k) { throw "myexn" }
   }
 }))