Added back helper file accidentally deleted during test block 219 migration.

tests/lib_2/mirrors/delegate_test.dart

Index: tests/lib_2/mirrors/delegate_test.dart
diff --git a/tests/lib_strong/mirrors/delegate_test.dart b/tests/lib_2/mirrors/delegate_test.dart
similarity index 95%
rename from tests/lib_strong/mirrors/delegate_test.dart
rename to tests/lib_2/mirrors/delegate_test.dart
index 7283b6a8e94c5c4b75a68d162966b0a6c8bc3717..4c63f28392da17bd9a0fe94ada496ccf894b95ab 100644
--- a/tests/lib_strong/mirrors/delegate_test.dart
+++ b/tests/lib_2/mirrors/delegate_test.dart
@@ -15,7 +15,6 @@ class C {
   get getter => 'g';
   set setter(x) {
     field = x * 2;
-    return 'unobservable value';
   }
 
   var field;
@@ -29,7 +28,7 @@ class Proxy {
 
 main() {
   var c = new C();
-  var proxy = new Proxy(c);
+  dynamic proxy = new Proxy(c);
   var result;
 
   Expect.equals('X-Y-Z', proxy.method('X', 'Y', 'Z'));