Fix warnings_checker.dart handling of multitests

tests/language_strong/const_constructor3_test.dart

Index: tests/language_strong/const_constructor3_test.dart
diff --git a/tests/language_strong/const_constructor3_test.dart b/tests/language_strong/const_constructor3_test.dart
index 2f1353aa27f5b1dae7550781b0468fd290a136a7..0a13ca70e89a054440407cb45aec0a14ec51f90b 100644
--- a/tests/language_strong/const_constructor3_test.dart
+++ b/tests/language_strong/const_constructor3_test.dart
@@ -11,14 +11,14 @@ class D extends C {
   const D(var d) : super(d);
 }
 
-const c = const C(0.0); /// 01: ok
-const d = const C(0); /// 02: static type warning, checked mode compile-time error
-const e = const D(0.0); /// 03: ok
-const f = const D(0); /// 04: checked mode compile-time error
+const c = const C(0.0); //# 01: ok
+const d = const C(0); //# 02: static type warning, checked mode compile-time error
+const e = const D(0.0); //# 03: ok
+const f = const D(0); //# 04: checked mode compile-time error
 
 main() {
-  print(c); /// 01: continued
-  print(d); /// 02: continued
-  print(e); /// 03: continued
-  print(f); /// 04: continued
+  print(c); //# 01: continued
+  print(d); //# 02: continued
+  print(e); //# 03: continued
+  print(f); //# 04: continued
 }