Fix warnings_checker.dart handling of multitests

tests/language_strong/issue18628_1_test.dart

Index: tests/language_strong/issue18628_1_test.dart
diff --git a/tests/language_strong/issue18628_1_test.dart b/tests/language_strong/issue18628_1_test.dart
index 9481efde14418a06ddc65b1c5d7ba27ff7300109..3856b3e7457f20843a369b62b9e8eeeb2ea65eb5 100644
--- a/tests/language_strong/issue18628_1_test.dart
+++ b/tests/language_strong/issue18628_1_test.dart
@@ -11,10 +11,10 @@
 class C<T> {
   // This line is supposed to cause the warning; the other commented
   // line just doesn't make sense without this line.
-  T t = int; /// 01: static type warning
+  T t = int; //# 01: static type warning
 }
 
 main() {
   C<Type> c = new C<Type>();
-  print(c.t); /// 01: static type warning
+  print(c.t); //# 01: static type warning
 }