Fix warnings_checker.dart handling of multitests

tests/language_strong/malformed_bound_test.dart

Index: tests/language_strong/malformed_bound_test.dart
diff --git a/tests/language_strong/malformed_bound_test.dart b/tests/language_strong/malformed_bound_test.dart
index 061c3b9453c829d4ee83da1c7dc55ee51e198ed8..c1845ffb0d7e39fd89ad04665a9ce7a5a9ca235e 100644
--- a/tests/language_strong/malformed_bound_test.dart
+++ b/tests/language_strong/malformed_bound_test.dart
@@ -5,13 +5,13 @@
 // Test that a malformed type variable bound is treated as dynamic.
 
 class C<T
-  extends Malformed /// 01: static type warning, runtime error
+  extends Malformed //# 01: static type warning, runtime error
 > {
-  f(T t) => t.foo; /// 01: continued
+  f(T t) => t.foo; //# 01: continued
 }
 
 main() {
   new C<int>()
-    .f(1) /// 01: continued
+    .f(1) //# 01: continued
   ;
 }