anchor.diff:  void main(List<String> arguments) {
     bool verbose = false;
     bool printJs = false;
  +  bool writeJs = false;
     List<int> indices;
     for (String arg in arguments) {
       if (arg == '-v') {
         verbose = true;
       } else if (arg == '--print-js') {
         printJs = true;
  +    } else if (arg == '--write-js') {
  +      writeJs = true;
       } else {
         int index = int.parse(arg, onError: (_) => null);
         if (index != null) {
  
positive.code:   CompilationResult compilationResult = await entry.internalMain(arguments);
    Expect.isTrue(compilationResult.isSuccess,
        "Unsuccessful compilation of test:\n${test.code}");
    CompilerImpl compiler = compilationResult.compiler;
    SingleMapping sourceMap = new SingleMapping.fromJson(
        JSON.decode(new File('$output.map').readAsStringSync()));
  
    if (printJs) {
      print('JavaScript output:');
      print(new File(output).readAsStringSync());
    }
    print("Running d8 $output");
    ProcessResult runResult = Process.runSync(d8executable,
  
negative.code: }
  class Class {
    @NoInline()
    @{2:Class}Class() {
      @{3:Class}throw '$EXCEPTION_MARKER';
    }
  }
  ''',
  