Revert CL https://codereview.chromium.org/14217011/, one test fails in minified mode.

tests/compiler/dart2js/simple_inferrer_unregister_call_test.dart

Index: tests/compiler/dart2js/simple_inferrer_unregister_call_test.dart
===================================================================
--- tests/compiler/dart2js/simple_inferrer_unregister_call_test.dart	(revision 22005)
+++ tests/compiler/dart2js/simple_inferrer_unregister_call_test.dart	(working copy)
@@ -1,45 +0,0 @@
-// Copyright (c) 2013, 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';
-
-import 'compiler_helper.dart';
-import 'parser_helper.dart';
-
-const String TEST = """
-var a = '';
-class A {
-  operator+(other) => other;
-}
-
-foo() {
-  // The following '+' call will first say that it may call A::+,
-  // String::+, or int::+. After all methods have been analyzed, we know
-  // that a is of type String, and therefore, this method cannot call
-  // A::+. Therefore, the type of the parameter of A::+ will be the
-  // one given by the other calls.
-  return a + 'foo';
-}
-
-main() {
-  new A() + 42;
-  foo();
-}
-""";
-
-
-void main() {
-  Uri uri = new Uri.fromComponents(scheme: 'source');
-  var compiler = compilerFor(TEST, uri);
-  compiler.runCompiler(uri);
-  var typesInferrer = compiler.typesTask.typesInferrer;
-
-  checkReturnInClass(String className, String methodName, type) {
-    var cls = findElement(compiler, className);
-    var element = cls.lookupLocalMember(buildSourceString(methodName));
-    Expect.equals(type, typesInferrer.internal.returnTypeOf[element]);
-  }
-
-  checkReturnInClass('A', '+', typesInferrer.intType);
-}