anchor.diff:      show LibraryInfo;
   import 'package:_fe_analyzer_shared/src/util/options.dart';
   import 'package:compiler/src/kernel/dart2js_target.dart';
  +import 'package:compiler/src/options.dart' as dart2jsOptions
  +    show CompilerOptions;
   import 'package:dev_compiler/src/kernel/target.dart';
   import 'package:front_end/src/api_prototype/compiler_options.dart'
       show
  
positive.code:       target = new TestTargetWrapper(new NoneTarget(targetFlags), targetFlags);
        break;
      case "dart2js":
        target = new TestDart2jsTarget('dart2js', targetFlags);
        break;
      case "dartdevc":
        target = new TestDevCompilerTarget(targetFlags);
  
negative.code:   @override
    final TestTargetFlags flags;
  
    TestDart2jsTarget(String name, this.flags,
        {dart2jsOptions.CompilerOptions? options})
        : super(name, flags, options: options);
  }
  
  class TestDevCompilerTarget extends DevCompilerTarget
  