anchor.diff:    String get dartShellFileName {
       var name = configuration['dart'];
       if (name == '') {
  -      name = '$buildDir/$executableName';
  -    }
  +      name = executablePath;
  +    }
  +
       TestUtils.ensureExists(name, configuration);
       return name;
     }
  
positive.code:   }
  
    /**
     * The file name of the executable used to run this suite's tests.
     */
    String get executableName {
      String suffix = getExecutableSuffix(configuration['compiler']);
      switch (configuration['compiler']) {
        case 'none':
          return 'dart$suffix';
        case 'dartc':
          return 'analyzer/bin/dart_analyzer$suffix';
        default:
          throw "Unknown executable for: ${configuration['compiler']}";
      }
  
negative.code:     var name;
      switch (configuration['compiler']) {
        case 'dartc':
          name = executablePath;
        case 'dart2js':
        case 'dart2dart':
          var prefix = 'sdk/bin/';
  