anchor.diff:      // Random when not set.
       if (mode == null || mode == '') {
         // Pick a mode at random (cluster), different from other.
  -      int cluster_modes = modes.length - 3;
  +      int cluster_modes = modes.length - 15;
         Random rand = new Random();
         do {
           mode = modes[rand.nextInt(cluster_modes)];
  
positive.code:     'aot-debug-arm64',
      'aot-arm64',
      // Too many divergences (due to arithmetic):
      'js'
    ];
  }
  
  
negative.code:   // Supported modes.
    static const List<String> modes = [
      // Cluster options:
      'jit-debug-ia32',
      'jit-debug-x64',
      'jit-debug-arm32',
  