Migrate first block of tests in standalone to standalone_2

tools/migration/bin/migrate_batch.dart

Index: tools/migration/bin/migrate_batch.dart
diff --git a/tools/migration/bin/migrate_batch.dart b/tools/migration/bin/migrate_batch.dart
index 67952664b7ba525e324ceb9ae59a77060b8c67af..1982830bf8673e148df6baa4a0a1f5fe85fe3f21 100644
--- a/tools/migration/bin/migrate_batch.dart
+++ b/tools/migration/bin/migrate_batch.dart
@@ -189,6 +189,7 @@ List<Fork> scanTests() {
   addFromDirectory("language_strong", "language_2");
   addFromDirectory("lib", "lib_2");
   addFromDirectory("lib_strong", "lib_2");
+  addFromDirectory("standalone", "standalone_2");
 
   // Include tests that have already been migrated too so we can show what
   // works remains to be done in them.
@@ -227,5 +228,6 @@ List<StatusFile> loadStatusFiles() {
   addStatusFile("language_strong");
   addStatusFile("lib");
   addStatusFile("lib_strong");
+  addStatusFile("standalone");
   return statusFiles;
 }