Let parser handle factory modifiers.

pkg/front_end/test/fasta/bootstrap_test.dart

Index: pkg/front_end/test/fasta/bootstrap_test.dart
diff --git a/pkg/front_end/test/fasta/bootstrap_test.dart b/pkg/front_end/test/fasta/bootstrap_test.dart
index 65bc2f81e6fc7c014ae44738a0c0c759bc67ce0f..8e23dee18e5d191e9f100e8216cc04ea5705bc4c 100644
--- a/pkg/front_end/test/fasta/bootstrap_test.dart
+++ b/pkg/front_end/test/fasta/bootstrap_test.dart
@@ -27,20 +27,17 @@ Future main() async {
   Uri sourceCompiler = await Isolate.resolvePackageUri(
       Uri.parse("package:front_end/src/fasta/bin/compile.dart"));
   Uri packages = await Isolate.packageConfig;
+  Directory tmp = await Directory.systemTemp.createTemp("fasta_bootstrap");
+  Uri compiledOnceCompiler = tmp.uri.resolve("fasta1.dill");
+  Uri compiledTwiceCompiler = tmp.uri.resolve("fasta2.dill");
   try {
-    Directory tmp = await Directory.systemTemp.createTemp("fasta_bootstrap");
-    Uri compiledOnceCompiler = tmp.uri.resolve("fasta1.dill");
-    Uri compiledTwiceCompiler = tmp.uri.resolve("fasta2.dill");
-    try {
-      await runCompiler(sourceCompiler, sourceCompiler, compiledOnceCompiler);
-      await runCompiler(
-          compiledOnceCompiler, sourceCompiler, compiledTwiceCompiler);
-    } finally {
-      await tmp.delete(recursive: true);
-    }
+    await runCompiler(sourceCompiler, sourceCompiler, compiledOnceCompiler);
+    await runCompiler(
+        compiledOnceCompiler, sourceCompiler, compiledTwiceCompiler);
   } finally {
-    asyncEnd();
+    await tmp.delete(recursive: true);
   }
+  asyncEnd();
 }
 
 Future runCompiler(Uri compiler, Uri input, Uri output) async {
@@ -49,9 +46,11 @@ Future runCompiler(Uri compiler, Uri input, Uri output) async {
   StdioProcess result = await StdioProcess.run(
       dartVm.toFilePath(),
       <String>[
+          "-c",
           compiler.toFilePath(),
           "--compile-sdk=${patchedSdk.toFilePath()}",
           "--output=${output.toFilePath()}",
+          "--verify",
           input.toFilePath(),
         ]);
   print(result.output);