Fix warnings_checker.dart handling of multitests

tests/lib/async/future_or_bad_type_test.dart

Index: tests/lib/async/future_or_bad_type_test.dart
diff --git a/tests/lib/async/future_or_bad_type_test.dart b/tests/lib/async/future_or_bad_type_test.dart
index 73e957ec78901cdac4716b09af6aca0129263375..07cb7176db2018ed249f4889f46b09c48cab39c6 100644
--- a/tests/lib/async/future_or_bad_type_test.dart
+++ b/tests/lib/async/future_or_bad_type_test.dart
@@ -10,9 +10,9 @@ import 'dart:async';
 import 'package:expect/expect.dart';
 
 class A
-    extends FutureOr<String> // /// extends: compile-time error
-    extends Object with FutureOr<bool> // /// with: compile-time error
-    implements FutureOr<int> // /// implements: compile-time error
+    extends FutureOr<String> // //# extends: compile-time error
+    extends Object with FutureOr<bool> // //# with: compile-time error
+    implements FutureOr<int> // //# implements: compile-time error
 {
 }
 
@@ -20,8 +20,8 @@ main() {
   // FutureOr<T> should be treated like `dynamic`. Dynamically the `T` is
   // completely ignored. It can be a malformed type.
   Expect.isTrue(499 is FutureOr<A>);
-  Expect.isTrue(499 is FutureOr<Does<Not<Exist>>>); // /// 00: static type warning
-  Expect.isTrue(499 is FutureOr<A, A>); //             /// 01: static type warning
+  Expect.isTrue(499 is FutureOr<Does<Not<Exist>>>); // //# 00: static type warning
+  Expect.isTrue(499 is FutureOr<A, A>); //             //# 01: static type warning
 
   var a = new A();
   Expect.isTrue(a.toString() is String);