Fix warnings_checker.dart handling of multitests

tests/language/compile_time_constant13_test.dart

Index: tests/language/compile_time_constant13_test.dart
diff --git a/tests/language/compile_time_constant13_test.dart b/tests/language/compile_time_constant13_test.dart
index b304132d2be94bc66803ff72d0f465cb5e10e6b8..89acf62fcf44fa2ce34e4b52efb1d1c125aaab14 100644
--- a/tests/language/compile_time_constant13_test.dart
+++ b/tests/language/compile_time_constant13_test.dart
@@ -3,18 +3,18 @@
 // BSD-style license that can be found in the LICENSE file.
 
 class A {
-  final x; //      /// 01: ok
+  final x; //      //# 01: ok
                  /// 02: compile-time error
-  var x; //        /// 03: compile-time error
-  get x => null; /// 04: compile-time error
-  set x(v) {} //   /// 05: compile-time error
+  var x; //        //# 03: compile-time error
+  get x => null; //# 04: compile-time error
+  set x(v) {} //   //# 05: compile-time error
 
   const A()
-    : x = 'foo' // /// 01: continued
-    : x = 'foo' // /// 02: continued
-    : x = 'foo' // /// 03: continued
-    : x = 'foo' // /// 04: continued
-    : x = 'foo' // /// 05: continued
+    : x = 'foo' // //# 01: continued
+    : x = 'foo' // //# 02: continued
+    : x = 'foo' // //# 03: continued
+    : x = 'foo' // //# 04: continued
+    : x = 'foo' // //# 05: continued
   ;
 }