Pass a Target instance to DillTarget instead of its name

pkg/front_end/tool/fasta_perf.dart

Index: pkg/front_end/tool/fasta_perf.dart
diff --git a/pkg/front_end/tool/fasta_perf.dart b/pkg/front_end/tool/fasta_perf.dart
index 1325cf7e400a349eef9c68d56fe88bd6b9918705..934bbe8e1f651ae267291220d8ccdc5d00b20c57 100644
--- a/pkg/front_end/tool/fasta_perf.dart
+++ b/pkg/front_end/tool/fasta_perf.dart
@@ -23,6 +23,7 @@ import 'package:front_end/src/fasta/translate_uri.dart';
 import 'package:front_end/src/fasta/parser/dart_vm_native.dart'
     show skipNativeClause;
 import 'package:kernel/target/targets.dart' show TargetFlags;
+import 'package:kernel/target/vm_fasta.dart' show VmFastaTarget;
 
 /// Cumulative total number of chars scanned.
 int inputSize = 0;
@@ -215,8 +216,8 @@ generateKernel(Uri entryUri,
 
   var timer = new Stopwatch()..start();
   final Ticker ticker = new Ticker();
-  final DillTarget dillTarget = new DillTarget(ticker, uriResolver, "vm_fasta",
-      flags: new TargetFlags(strongMode: strongMode));
+  final DillTarget dillTarget = new DillTarget(ticker, uriResolver,
+      new VmFastaTarget(new TargetFlags(strongMode: strongMode)));
   final KernelTarget kernelTarget =
       new KernelTarget(PhysicalFileSystem.instance, dillTarget, uriResolver);
   var entrypoints = [