Revert "Avoid "=== true" inside code by calling a function that does this for us."

tests/language/src/Operator5Test.dart

-// Copyright (c) 2012, 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.
-
-class A {
-  operator ==(other) => 1;
-  operator <(other) => null;
-  operator <=(other) => 499;
-  operator >(other) => "foo";
-  operator >=(other) => 42;
-}
-
-// This triggered a bug in Dart2Js: equality operator was always boolified.
-equals(a) {
-  try {
-    Expect.equals(1, a == a);
-  } catch(TypeError e) {
-    // In checked mode the test doesn't do anything.
-  }
-}
-
-equalsNull(a) {
-  try {
-    Expect.equals(1, a == null);
-  } catch(TypeError e) {
-    // In checked mode the test doesn't do anything.
-  }
-}
-
-less(a) {
-  try {
-    Expect.equals(null, a < a);
-  } catch(TypeError e) {}
-}
-
-lessEqual(a) {
-  try {
-    Expect.equals(499, a <= a);
-  } catch(TypeError e) {}
-}
-
-greater(a) {
-  try {
-    Expect.equals("foo", a > a);
-  } catch(TypeError e) {}
-}
-
-greaterEqual(a) {
-  try {
-    Expect.equals(42, a >= a);
-  } catch(TypeError e) {}
-}
-
-main() {
-  var a = new A();
-  equals(a);
-  less(a);
-  lessEqual(a);
-  greater(a);
-  greaterEqual(a);
-}