8058575: IllegalAccessError trying to access package-private class from VM anonymous class

Put anonymous classes in unnamed package into host class's package.  Throw exception if host class's package differs from anonymous class.

Reviewed-by: coleenp, acorn

hotspot/src/share/vm/classfile/verifier.cpp

@@ -2786,7 +2786,7 @@ void ClassVerifier::verify_invoke_instructions(
       // direct interface relative to the host class
       have_imr_indirect = (have_imr_indirect &&
                            !is_same_or_direct_interface(
-                             InstanceKlass::cast(current_class()->host_klass()),
+                             current_class()->host_klass(),
                              host_klass_type, ref_class_type));
     }
     if (!subtype) {