Inserting this into Actions.nqp stops the serialization of NQPMatch objects. For why?

Actions.nqp.diff

diff --git a/src/Perl6/Actions.nqp b/src/Perl6/Actions.nqp
index 29a19ea..c9a1648 100644
--- a/src/Perl6/Actions.nqp
+++ b/src/Perl6/Actions.nqp
@@ -2818,6 +2818,11 @@ class Perl6::Actions is HLL::Actions does STDActions {
                     $replacement[$i] := node_walker($node[$i]);
                     $i := $i + 2;
                 }
+                $i := 1;
+                while $i < $n {
+                    $replacement[$i].name;
+                    $i := $i + 2;
+                }
                 return clear_node($replacement);
             }