make say() and print() redispatch to the methods on $*OUT

src/core/IO.pm

@@ -1,14 +1,11 @@
 # XXX Relatively cheaty, just to get us able to output something.
 # But you should see what USED to be here! O.O
 sub print(*@list) {
-    nqp::print(@list.shift) while @list.gimme(1);
-    1.Bool
+    $*OUT.print: @list;
 }
 
 sub say(|$) {
-    my $args := pir::perl6_current_args_rpa__P();
-    print nqp::shift($args).gist while $args;
-    print "\n";
+    $*OUT.say: |pir__perl6_box_rpa__PP(pir::perl6_current_args_rpa__P());
 }
 
 sub gist(|$) {

src/core/Parcel.pm

@@ -79,6 +79,8 @@ my class Parcel {
     multi method DUMP(Parcel:D:) {
         self.DUMP-ID() ~ '(:storage(' ~ DUMP($!storage) ~ '))'
     }
+
+    method ARGLIST_FLATTENABLE() { $!storage }
 }
 
 
@@ -108,3 +110,4 @@ sub pir__perl6_box_rpa__PP(|$) {
 sub pir__perl6_unbox_rpa__PP(\$parcel) {
     pir::getattribute__PPPs($parcel, Parcel, '$!storage')
 }
+