Move `reify` to use fasta instead of dartk

pkg/kernel/test/closures_initializers/suite.dart

Index: pkg/kernel/test/closures_initializers/suite.dart
diff --git a/pkg/kernel/test/closures_initializers/suite.dart b/pkg/kernel/test/closures_initializers/suite.dart
index 81cc832cdae2fe627c97ff947cbb9ff9d64b4e39..1808371147a79c72ff17f9d7cdf986003620b066 100644
--- a/pkg/kernel/test/closures_initializers/suite.dart
+++ b/pkg/kernel/test/closures_initializers/suite.dart
@@ -13,6 +13,8 @@ import 'package:testing/testing.dart'
 
 import 'package:kernel/ast.dart' show Program, Library;
 
+import 'package:kernel/target/targets.dart' show Target;
+
 import 'package:kernel/transformations/argument_extraction_for_redirecting.dart'
     as argument_extraction;
 
@@ -34,6 +36,8 @@ const String STRONG_MODE = " strong mode ";
 class ClosureConversionContext extends ChainContext implements CompileContext {
   final bool strongMode;
 
+  Target get target => null;
+
   final List<Step> steps;
 
   ClosureConversionContext(this.strongMode, bool updateExpectations)