Add a missing guard in multi deferral

The callsame guard only cared for the types of the arguments, but not
the particular target multi. (Eventually this should be resolved by us
arranging to attach the dispatch caches for `callsame` and friends a
level up, but for now this gets us correct behavior.)

src/vm/moar/dispatchers.nqp

@@ -1971,6 +1971,13 @@ nqp::dispatch('boot-syscall', 'dispatcher-register', 'raku-multi-core',
             my $arg-capture := nqp::dispatch('boot-syscall', 'dispatcher-drop-arg', $init, 0);
             my $dispatch-plan := raku-multi-plan(@candidates, $arg-capture, 0);
 
+            # Put a guard on the dispatchees.
+            my $track-target := nqp::dispatch('boot-syscall', 'dispatcher-track-arg',
+                $init, 0);
+            nqp::dispatch('boot-syscall', 'dispatcher-guard-literal',
+                nqp::dispatch('boot-syscall', 'dispatcher-track-attr',
+                    $track-target, Routine, '@!dispatchees'));
+
             # We already called the first candidate in the trivial plan, so
             # drop it.
             $dispatch-plan := $dispatch-plan.next;
@@ -1987,8 +1994,6 @@ nqp::dispatch('boot-syscall', 'dispatcher-register', 'raku-multi-core',
                     $args := nqp::dispatch('boot-syscall', 'dispatcher-insert-arg',
                         $args, 0, $track-invocant);
                 }
-                my $track-target := nqp::dispatch('boot-syscall', 'dispatcher-track-arg',
-                    $init, 0);
                 my $with-target := nqp::dispatch('boot-syscall', 'dispatcher-insert-arg',
                     $args, 0, $track-target);
                 my $capture-with-plan := nqp::dispatch('boot-syscall',