Fix warnings_checker.dart handling of multitests

tests/language_strong/generic_methods_simple_as_expression_test.dart

Index: tests/language_strong/generic_methods_simple_as_expression_test.dart
diff --git a/tests/language_strong/generic_methods_simple_as_expression_test.dart b/tests/language_strong/generic_methods_simple_as_expression_test.dart
index bbfa54edd79447730dc5a58076c06506ca6d13f6..d6b3c48c21461d058222a3c8399af6234f5b1515 100644
--- a/tests/language_strong/generic_methods_simple_as_expression_test.dart
+++ b/tests/language_strong/generic_methods_simple_as_expression_test.dart
@@ -13,6 +13,6 @@ T cast<T>(dynamic obj) {
 }
 
 main() {
-  Expect.equals(cast<num>(42), 42); /// 01: ok
-  cast<String>(42); /// 02: runtime error
+  Expect.equals(cast<num>(42), 42); //# 01: ok
+  cast<String>(42); //# 02: runtime error
 }