Dump extra info about QAST::SpecialArg when dumping the AST.

Author: pmurias

src/QAST/SpecialArg.nqp

@@ -13,4 +13,17 @@ role QAST::SpecialArg {
         $!flat := $value unless $value =:= NO_VALUE;
         $!flat
     }
+
+    method dump_extra_node_info() {
+        my $parent := self.HOW.parents(self, :local(1))[0];
+        my $info := $parent.HOW.method_table($parent)<dump_extra_node_info>(self);
+
+        $info := nqp::chars($info) ?? $info ~ " " !! "";
+
+        if $!flat {
+            $info ~ ":flat" ~ ($!named ?? " :named" !! "");
+        } else {
+            $info ~ ($!named ?? ":named<$!named>" !! "");
+        }
+    }
 }