Refactor least upper bound computation; support bottom correctly.

pkg/analyzer/test/generated/test_all.dart

 // Copyright (c) 2014, 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.
 
 library test.generated;
 
 import 'package:unittest/unittest.dart';
 
 import 'all_the_rest_test.dart' as all_the_rest;
 import 'ast_test.dart' as ast_test;
 import 'compile_time_error_code_test.dart' as compile_time_error_code_test;
 import 'element_test.dart' as element_test;
 import 'engine_test.dart' as engine_test;
 import 'incremental_resolver_test.dart' as incremental_resolver_test;
 import 'incremental_scanner_test.dart' as incremental_scanner_test;
 import 'java_core_test.dart' as java_core_test;
 import 'java_io_test.dart' as java_io_test;
 import 'non_error_resolver_test.dart' as non_error_resolver_test;
 import 'parser_test.dart' as parser_test;
 import 'resolver_test.dart' as resolver_test;
 import 'scanner_test.dart' as scanner_test;
 import 'static_type_warning_code_test.dart' as static_type_warning_code_test;
 import 'static_warning_code_test.dart' as static_warning_code_test;
+import 'type_system_test.dart' as type_system_test;
 import 'utilities_test.dart' as utilities_test;
 
 /// Utility for manually running all tests.
 main() {
   groupSep = ' | ';
   group('generated tests', () {
     all_the_rest.main();
     ast_test.main();
     compile_time_error_code_test.main();
     element_test.main();
     engine_test.main();
     incremental_resolver_test.main();
     incremental_scanner_test.main();
     java_core_test.main();
     java_io_test.main();
     non_error_resolver_test.main();
     parser_test.main();
     resolver_test.main();
     scanner_test.main();
     static_type_warning_code_test.main();
     static_warning_code_test.main();
+    type_system_test.main();
     utilities_test.main();
   });
 }