Revert of Revert of [es6] Bound function names

test/mjsunit/function-bind-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.
+
+function f() {}
+var fb = f.bind({});
+assertEquals('bound f', fb.name);
+assertEquals('function bound f() { [native code] }', fb.toString());
+
+Object.defineProperty(f, 'name', {value: 42});
+var fb2 = f.bind({});
+assertEquals('bound ', fb2.name);
+assertEquals('function bound () { [native code] }', fb2.toString());