Fix warnings_checker.dart handling of multitests

tests/language/wrong_number_type_arguments_test.dart

Index: tests/language/wrong_number_type_arguments_test.dart
diff --git a/tests/language/wrong_number_type_arguments_test.dart b/tests/language/wrong_number_type_arguments_test.dart
index 4cfa40bf5b909182e5562162ada7d1e988de1fe1..bc1da3297235525dab9fe5558aa314bac2f5af6a 100644
--- a/tests/language/wrong_number_type_arguments_test.dart
+++ b/tests/language/wrong_number_type_arguments_test.dart
@@ -6,16 +6,16 @@ import "package:expect/expect.dart";
 
 // Map takes 2 type arguments.
 Map
-<String> /// 00: static type warning
+<String> //# 00: static type warning
 foo;
 Map
-<String> /// 02: static type warning
+<String> //# 02: static type warning
 baz;
 
 main() {
   foo = null;
   var bar = new Map
-  <String> /// 01: static type warning
+  <String> //# 01: static type warning
   ();
-  baz = new Map(); /// 02: continued
+  baz = new Map(); //# 02: continued
 }