Don't reflect ES2015 Function name inference in Function.prototype.toString

test/mjsunit/harmony/function-name.js

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // Flags: --harmony-function-name
 // Flags: --harmony-destructuring-bind --harmony-destructuring-assignment
 
 (function testVariableDeclarationsFunction() {
   'use strict';
   var a = function(){};
@@ skipping 339 matching lines @@
   assertEquals('[1]', class1[sym1].name);
 })();
 
 
 (function testComputedNamesOnlyAppliedSyntactically() {
   function factory() { return () => {}; }
 
   var obj = { ['foo']: factory() };
   assertEquals('', obj.foo.name);
 })();
+
+
+(function testNameNotReflectedInToString() {
+  var f = function() {};
+  var g = function*() {};
+  var obj = {
+    ['h']: function() {},
+    i: () => {}
+  };
+  assertEquals('function () {}', f.toString());
+  assertEquals('function* () {}', g.toString());
+  assertEquals('function () {}', obj.h.toString());
+  assertEquals('() => {}', obj.i.toString());
+})();