Fix Harmony sets and maps to allow undefined as keys.

test/mjsunit/harmony/collections.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 55 matching lines @@
 function TestSet(set, key) {
   assertFalse(set.has(key));
   set.add(key);
   assertTrue(set.has(key));
   set.delete(key);
   assertFalse(set.has(key));
 }
 function TestSetBehavior(set) {
   for (var i = 0; i < 20; i++) {
     TestSet(set, new Object);
+    TestSet(set, i);
+    TestSet(set, i / 100);
+    TestSet(set, 'key-' + i);
+  }
+  var keys = [ +0, -0, +Infinity, -Infinity, true, false, null, undefined ];
+  for (var i = 0; i < keys.length; i++) {
+    TestSet(set, keys[i]);
   }
 }
-TestSet(new Set, 23);
-TestSet(new Set, 'foo');
 TestSetBehavior(new Set);
 
 
 // Test expected mapping behavior for Maps and WeakMaps
 function TestMapping(map, key, value) {
   map.set(key, value);
   assertSame(value, map.get(key));
 }
 function TestMapBehavior1(m) {
   TestMapping(m, new Object, 23);
   TestMapping(m, new Object, 'the-value');
   TestMapping(m, new Object, new Object);
 }
 TestMapBehavior1(new Map);
 TestMapBehavior1(new WeakMap);
 
 
 // Test expected mapping behavior for Maps only
 function TestMapBehavior2(m) {
   for (var i = 0; i < 20; i++) {
     TestMapping(m, i, new Object);
     TestMapping(m, i / 10, new Object);
     TestMapping(m, 'key-' + i, new Object);
   }
-  var keys = [ +0, -0, +Infinity, -Infinity, true, false, null ];
+  var keys = [ +0, -0, +Infinity, -Infinity, true, false, null, undefined ];
   for (var i = 0; i < keys.length; i++) {
     TestMapping(m, keys[i], new Object);
   }
 }
 TestMapBehavior2(new Map);
 
 
 // Test expected querying behavior of Maps and WeakMaps
 function TestQuery(m) {
   var key = new Object;
@@ skipping 151 matching lines @@
   configurable: true,
   writable: true
 }});
 assertEquals(10, o.myValue);
 
 
 // Stress Test
 // There is a proposed stress-test available at the es-discuss mailing list
 // which cannot be reasonably automated.  Check it out by hand if you like:
 // https://mail.mozilla.org/pipermail/es-discuss/2011-May/014096.html