ES6 symbols: fix corner cases of equality operators

test/mjsunit/harmony/symbols.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 113 matching lines @@
 function TestToNumber() {
   for (var i in symbols) {
     assertSame(NaN, Number(symbols[i]).valueOf())
     assertSame(NaN, symbols[i] + 0)
   }
 }
 TestToNumber()
 
 
 function TestEquality() {
-  // Every symbol should equal itself.
+  // Every symbol should equal itself, and non-strictly equal its wrapper.
   for (var i in symbols) {
     assertSame(symbols[i], symbols[i])
     assertEquals(symbols[i], symbols[i])
     assertTrue(Object.is(symbols[i], symbols[i]))
     assertTrue(symbols[i] === symbols[i])
     assertTrue(symbols[i] == symbols[i])
+    assertFalse(symbols[i] === new Symbol(symbols[i]))
+    assertFalse(new Symbol(symbols[i]) === symbols[i])
+    assertTrue(symbols[i] == new Symbol(symbols[i]))
+    assertTrue(new Symbol(symbols[i]) == symbols[i])
   }
 
   // All symbols should be distinct.
   for (var i = 0; i < symbols.length; ++i) {
     for (var j = i + 1; j < symbols.length; ++j) {
       assertFalse(Object.is(symbols[i], symbols[j]))
       assertFalse(symbols[i] === symbols[j])
       assertFalse(symbols[i] == symbols[j])
     }
   }
+
+  // Symbols should not be equal to any other value (and the test terminates).
+  var values = [347, 1.275, NaN, "string", null, undefined, {}, function() {}]
+  for (var i in symbols) {
+    for (var j in values) {
+      assertFalse(symbols[i] === values[j])
+      assertFalse(values[j] === symbols[i])
+      assertFalse(symbols[i] == values[j])
+      assertFalse(values[j] == symbols[i])
+    }
+  }
 }
 TestEquality()
 
 
 function TestGet() {
   for (var i in symbols) {
     assertThrows(function() { symbols[i].toString() }, TypeError)
     assertEquals(symbols[i], symbols[i].valueOf())
     assertEquals(undefined, symbols[i].a)
     assertEquals(undefined, symbols[i]["a" + "b"])
@@ skipping 130 matching lines @@
   var obj = objs[i]
   TestKeySet(obj)
   TestKeyDefine(obj)
   TestKeyGet(obj)
   TestKeyHas(obj)
   TestKeyEnum(obj)
   TestKeyNames(obj)
   TestKeyDescriptor(obj)
   TestKeyDelete(obj)
 }