Fix warnings_checker.dart handling of multitests

tests/language/static_setter_get_test.dart

Index: tests/language/static_setter_get_test.dart
diff --git a/tests/language/static_setter_get_test.dart b/tests/language/static_setter_get_test.dart
index a10c1d9205982a1e479f51c3c9b0cc7ec8ed4533..1680a2d3c4447d11d7f9aa3383934ba79cedc3c0 100644
--- a/tests/language/static_setter_get_test.dart
+++ b/tests/language/static_setter_get_test.dart
@@ -6,10 +6,10 @@ import 'package:expect/expect.dart';
 
 class Class {
   static set o(_) {}
-  m() => o; /// 01: static type warning
+  m() => o; //# 01: static type warning
   noSuchMethod(_) => 42;
 }
 
 main() {
-  Expect.throws(() => new Class().m()); /// 01: continued
+  Expect.throws(() => new Class().m()); //# 01: continued
 }