Fix warnings_checker.dart handling of multitests

tests/language_strong/issue15606_test.dart

Index: tests/language_strong/issue15606_test.dart
diff --git a/tests/language_strong/issue15606_test.dart b/tests/language_strong/issue15606_test.dart
index d50b576b54a76d5fa0f49294f14792e757ce836e..ea963d7664cbb08213df56349a8eb2d584bb77d4 100644
--- a/tests/language_strong/issue15606_test.dart
+++ b/tests/language_strong/issue15606_test.dart
@@ -9,13 +9,13 @@ var a = [new Object(), 42];
 main() {
   while (false) { // Comply to inlining heuristics.
     // Use an unresolved prefix.
-    var foo = Unresolved.foo( /// 01: static type warning
+    var foo = Unresolved.foo( //# 01: static type warning
       // Make dart2js generate a call to setRuntimeTypeInfo.
-      new Foo<int>(), /// 01: continued
+      new Foo<int>(), //# 01: continued
       // Use a one-shot interceptor.
-      a[0].toString()); /// 01: continued
+      a[0].toString()); //# 01: continued
 
     // Do an is test on `Foo` to require setRuntimeTypeInfo.
-    print(foo is Foo<int>); /// 01: continued
+    print(foo is Foo<int>); //# 01: continued
   }
 }