Revert "dart2js: Refactoring, documentation, and a few bugfixes in Namer class."

tests/language/is_operator_clash_test.dart

-// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-import "package:expect/expect.dart";
-
-class A {
-}
-
-class $B extends A {
-}
-
-class C implements $B {
-  // Try to clash with dart2js's isCLASS field.
-  var isB = false;
-  var $isB = false;
-  var is$B = false;
-  var is$$B = false;
-  var $is$B = false;
-
-  var isA = false;
-  var $isA = false;
-  var is$A = false;
-  var is$$A = false;
-  var $is$A = false;
-}
-
-int inscrutable(int x) => x == 0 ? 0 : x | inscrutable(x & (x - 1));
-
-main() {
-  var things = [new A(), new $B(), new C()];
-
-  var a = things[inscrutable(0)];
-  Expect.isTrue(a is A);
-  Expect.isFalse(a is $B);
-  Expect.isFalse(a is C);
-
-  var b = things[inscrutable(1)];
-  Expect.isTrue(b is A);
-  Expect.isTrue(b is $B);
-  Expect.isFalse(b is C);
-
-  var c = things[inscrutable(2)];
-  Expect.isTrue(c is A);
-  Expect.isTrue(c is $B);
-  Expect.isTrue(c is C);
-}