Reapply "reflectType() dynamic type arguments support (#26012)"

tests/lib/mirrors/mirrors_used_generic_types_test.dart

Index: tests/lib/mirrors/mirrors_used_generic_types_test.dart
diff --git a/tests/lib/mirrors/mirrors_used_generic_types_test.dart b/tests/lib/mirrors/mirrors_used_generic_types_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..59622149ac241e1d4c091e3234d9ebe735a840b5
--- /dev/null
+++ b/tests/lib/mirrors/mirrors_used_generic_types_test.dart
@@ -0,0 +1,28 @@
+// Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library Test;
+
+@MirrorsUsed(targets: const ["Test"])
+import 'dart:mirrors';
+import 'dart:async';
+
+import 'package:expect/expect.dart';
+
+class A {
+  // Because of the `mirrors-used` annotation, the types `List` and `Future`
+  // are not reflectable.
+  // However, we still need to be able to create a Mirror for them, when we
+  // create a mirror for `foo`. In particular, it must be able to create a
+  // mirror, even though there are generic types.
+  List<int> foo(Future<int> x) {
+    return null;
+  }
+}
+
+void main() {
+  var m = reflect(new A()).type.instanceMembers[#foo];
+  Expect.equals(#List, m.returnType.simpleName);
+  Expect.equals(#Future, m.parameters[0].type.simpleName);
+}