Fix #11466: add test

Author: liufengyun

tests/neg/i114666.scala

@@ -0,0 +1,9 @@
+open class GraphDB[Id]:
+  class Node private[GraphDB](val id: Id)
+end GraphDB
+
+object graph extends GraphDB[String]
+import graph.*
+
+@main
+def Test = new Node("Alice") // error