Checking that the current PMC isn't NULL before using it in visit_loop_todo_list().
Checking that the current PMC isn't NULL before using it in
visit_loop_todo_list().


git-svn-id: 6e74a02f85675cec270f5d931b0f6998666294a3@20874 d31e2699-5ff4-0310-a27c-f18f2fbe73fe

ashgti/parrot,ashgti/parrot,ashgti/parrot,ashgti/parrot,ashgti/parrot,ashgti/parrot,ashgti/parrot