Upgrade Symbol implementation to match current ES6 behavior.

test/mjsunit/harmony/private.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 24 matching lines @@
   for (var i = 0; i < 2; ++i) {
     for (var j = 0; j < 5; ++j) {
       symbols.push(%CreatePrivateSymbol("66"))
       symbols.push(Object(%CreatePrivateSymbol("66")).valueOf())
     }
     gc()  // Promote existing symbols and then allocate some more.
   }
 }
 TestNew()
 
-
 function TestType() {
   for (var i in symbols) {
     assertEquals("symbol", typeof symbols[i])
     assertTrue(typeof symbols[i] === "symbol")
     assertTrue(%SymbolIsPrivate(symbols[i]))
     assertEquals(null, %_ClassOf(symbols[i]))
-    assertEquals("Symbol", %_ClassOf(new Symbol(symbols[i])))
     assertEquals("Symbol", %_ClassOf(Object(symbols[i])))
   }
 }
 TestType()
 
 
 function TestPrototype() {
   for (var i in symbols) {
     assertSame(Symbol.prototype, symbols[i].__proto__)
   }
 }
 TestPrototype()
 
 
 function TestConstructor() {
   for (var i in symbols) {
-    assertSame(Symbol, symbols[i].__proto__.constructor)
+    assertSame(Function, symbols[i].__proto__.constructor)
+    assertSame(Symbol, Object(symbols[i]).__proto__.constructor)
   }
 }
 TestConstructor()
 
 
-function TestName() {
+function TestValueOf() {
   for (var i in symbols) {
-    var name = symbols[i].name
-    assertTrue(name === "66")
+    var value = Object(symbols[i]).valueOf()
+    assertTrue(value === symbols[i])
   }
 }
-TestName()
+TestValueOf()
 
 
 function TestToString() {
   for (var i in symbols) {
     assertThrows(function() { String(symbols[i]) }, TypeError)
     assertThrows(function() { symbols[i] + "" }, TypeError)
     assertThrows(function() { symbols[i].toString() }, TypeError)
-    assertThrows(function() { (new Symbol(symbols[i])).toString() }, TypeError)
-    assertThrows(function() { Object(symbols[i]).toString() }, TypeError)
+    assertThrows(function() { (Symbol(symbols[i])).toString() }, TypeError)
+    assertDoesNotThrow(function() { Object(symbols[i]).toString() })
     assertEquals("[object Symbol]", Object.prototype.toString.call(symbols[i]))
   }
 }
 TestToString()
 
 
 function TestToBoolean() {
   for (var i in symbols) {
     assertTrue(Boolean(symbols[i]).valueOf())
     assertFalse(!symbols[i])
@@ skipping 20 matching lines @@
 
 
 function TestEquality() {
   // 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])
+    assertTrue(symbols[i] === (Object(symbols[i])).valueOf())
+    assertTrue((Object(symbols[i])).valueOf() === symbols[i])
+    assertTrue(symbols[i] == (Object(symbols[i])).valueOf())
+    assertTrue((Object(symbols[i])).valueOf() == 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(symbols[i], Object(symbols[i]).valueOf())
     assertEquals(undefined, symbols[i].a)
     assertEquals(undefined, symbols[i]["a" + "b"])
     assertEquals(undefined, symbols[i]["" + "1"])
     assertEquals(undefined, symbols[i][62])
   }
 }
 TestGet()
 
 
 function TestSet() {
   for (var i in symbols) {
     symbols[i].toString = 0
     assertThrows(function() { symbols[i].toString() }, TypeError)
     symbols[i].valueOf = 0
-    assertEquals(symbols[i], symbols[i].valueOf())
+    assertEquals(symbols[i], Object(symbols[i]).valueOf())
     symbols[i].a = 0
     assertEquals(undefined, symbols[i].a)
     symbols[i]["a" + "b"] = 0
     assertEquals(undefined, symbols[i]["a" + "b"])
     symbols[i][62] = 0
     assertEquals(undefined, symbols[i][62])
   }
 }
 TestSet()
 
@@ skipping 126 matching lines @@
   // but not between scavenges.  This must also apply for symbol keys.
   var key = Symbol("key");
   var a = {};
   a[key] = "abc";
 
   for (var i = 0; i < 100000; i++) {
     a[key] += "a";  // Allocations cause a scavenge.
   }
 }
 TestCachedKeyAfterScavenge();