Pass a Target instance to DillTarget instead of its name

pkg/front_end/lib/src/fasta/compile_platform.dart

Index: pkg/front_end/lib/src/fasta/compile_platform.dart
diff --git a/pkg/front_end/lib/src/fasta/compile_platform.dart b/pkg/front_end/lib/src/fasta/compile_platform.dart
index a9863e198e78ac2c0692872e05bfc80bb49221b6..632248b49a0d402d1f64770f41a33cb865e95694 100644
--- a/pkg/front_end/lib/src/fasta/compile_platform.dart
+++ b/pkg/front_end/lib/src/fasta/compile_platform.dart
@@ -24,7 +24,7 @@ import 'ticker.dart' show Ticker;
 
 import 'translate_uri.dart' show TranslateUri;
 
-import 'package:kernel/target/targets.dart' show TargetFlags;
+import 'package:kernel/target/targets.dart' show getTarget, TargetFlags;
 
 const int iterations = const int.fromEnvironment("iterations", defaultValue: 1);
 
@@ -74,8 +74,10 @@ Future compilePlatformInternal(CompilerContext c, Ticker ticker, Uri patchedSdk,
   ticker.logMs("Read packages file");
 
   DillTarget dillTarget = new DillTarget(
-      ticker, uriTranslator, c.options.target,
-      flags: new TargetFlags(strongMode: c.options.strongMode));
+      ticker,
+      uriTranslator,
+      getTarget(
+          c.options.target, new TargetFlags(strongMode: c.options.strongMode)));
   KernelTarget kernelTarget =
       new KernelTarget(c.fileSystem, dillTarget, uriTranslator, c.uriToSource);