Add test case

Author: odersky

tests/pos/avoid.scala

@@ -8,3 +8,20 @@ object test {
   }
   val z: String = x.y
 }
+
+// A tricky case involving inner classes, exercised
+// in the large in dotty.tools.dotc.core.NameKinds.scala.
+object Test2 {
+
+  class NK {
+    class I
+    type T
+  }
+
+  val x = new NK { type T = I }
+
+  val y = {
+    class C extends NK { type T = I }
+    new C
+  }
+}