Handle ambiguous prefix members.

tests/language/regress_19413_test.dart

 // Copyright (c) 2014, 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.
 
-// Test that a type variable is not in scope for metadata declared on the type
-// declaration.
+// Regression test for issue 19413.
 
-@deprecated
-class Foo
-<deprecated>  /// 01: ok
-{}
+import 'regress_19413_foo.dart' as foo;
+import 'regress_19413_bar.dart' as foo;
 
 main() {
-  Foo f = null;
-}
+  foo.f(); /// 01: static type warning, runtime error
+}