anchor.diff:  import 'package:front_end/src/fasta/scanner/io.dart' show readBytesFromFileSync;
   import 'package:front_end/src/fasta/source/directive_listener.dart';
   import 'package:front_end/src/fasta/uri_translator.dart' show UriTranslator;
  +
  +import 'package:kernel/target/targets.dart' show TargetFlags;
  +import 'package:kernel/target/vm.dart' show VmTarget;
   
   /// Cumulative total number of chars scanned.
   int inputSize = 0;
  
positive.code:       help: 'run the compiler in legacy-mode',
        defaultsTo: false,
        negatable: false);
  
negative.code:   scanReachableFiles(entryUri);
  
    var timer = new Stopwatch()..start();
    var flags = new TargetFlags(strongMode: strongMode);
    var options = new CompilerOptions()
      ..sdkRoot = sdkRoot
      ..strongMode = strongMode
      ..target = (strongMode ? new VmTarget(flags) : new LegacyVmTarget(flags))
      ..chaseDependencies = true
      ..packagesFileUri = Uri.base.resolve('.packages')
      ..compileSdk = compileSdk;
  