Simple test for crash involving multicast loopback and stale dst.
Reuse exising NAT46 program.
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250610001245.1981782-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>