Type-import-on-demand (import pack.*; ) makes private nested types (classes, enums...) visible.
It is true for JDK9 b42 with new import behavior.

For example, the following test will compile without errors:

package pack;
import pack.A.Outer.*;

class A {
    static class Outer<X extends Inner> {
        private static class Inner{}
     }
}

The failed JCK tests are:
lang/PKGS/pkgs087/pkgs08701m1e03/pkgs08701m1e03.html