Fix warnings_checker.dart handling of multitests

tests/corelib/iterable_generate_test.dart

Index: tests/corelib/iterable_generate_test.dart
diff --git a/tests/corelib/iterable_generate_test.dart b/tests/corelib/iterable_generate_test.dart
index 81e69e2c2711c111ee8fdccd49c83b3101c29267..ca6ba3adeeac34d4b8610d81f589c98db3e9bced 100644
--- a/tests/corelib/iterable_generate_test.dart
+++ b/tests/corelib/iterable_generate_test.dart
@@ -59,12 +59,12 @@ main() {
 
   // Invalid types:
   Expect.throws(() => new Iterable<String>.generate(5));
-  if (checkedMode) { //                                                 /// 01: ok
-    Expect.throws(() => new Iterable<Null>.generate(5).elementAt(2)); /// 01: continued
-  } else { //                                                           /// 01: continued
-    Iterable<dynamic> iter5 = new Iterable<Null>.generate(5); //        /// 01: continued
-    Expect.equals(2, iter5.elementAt(2)); //                            /// 01: continued
-  } //                                                                  /// 01: continued
+  if (checkedMode) { //                                                 //# 01: ok
+    Expect.throws(() => new Iterable<Null>.generate(5).elementAt(2)); //# 01: continued
+  } else { //                                                           //# 01: continued
+    Iterable<dynamic> iter5 = new Iterable<Null>.generate(5); //        //# 01: continued
+    Expect.equals(2, iter5.elementAt(2)); //                            //# 01: continued
+  } //                                                                  //# 01: continued
   Expect.throws(() => new Iterable<bool>.generate(5));
 
   // Regression: https://github.com/dart-lang/sdk/issues/26358