Apply the deepmap fix to nodemap too

src/core/metaops.pm

@@ -516,7 +516,7 @@ multi sub deepmap(\op, Associative \h) {
 proto sub nodemap(|) { * }
 multi sub nodemap(\op, \obj) {
     my Mu $rpa := nqp::list();
-    my Mu $items := nqp::getattr(obj.List, List, '$!reified');
+    my Mu $items := obj.FLATTENABLE_LIST;
     my Mu $o;
     # We process the elements in two passes, end to start, to
     # prevent users from relying on a sequential ordering of hyper.