Access parameter data in Annotations, as well as fixed export visibility

pkg/docgen/test/multi_library_code/lib/test_lib2_bar.dart

Index: pkg/docgen/test/multi_library_code/lib/test_lib2_bar.dart
diff --git a/tests/language/deferred_constraints_lib2.dart b/pkg/docgen/test/multi_library_code/lib/test_lib2_bar.dart
similarity index 85%
copy from tests/language/deferred_constraints_lib2.dart
copy to pkg/docgen/test/multi_library_code/lib/test_lib2_bar.dart
index 830705f0cd4e96f3a5355dff33001eebc4b134fe..1a07d2bfcbec000ca259946fd3598f181039ec0b 100644
--- a/tests/language/deferred_constraints_lib2.dart
+++ b/pkg/docgen/test/multi_library_code/lib/test_lib2_bar.dart
@@ -2,6 +2,8 @@
 // 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.
 
-foo() => 42;
+library test_lib2_bar;
 
-class C {}
+class Bar {
+
+}