darwin_stop_world.c (GC_push_all_stacks, [...]): Call vm_deallocate to free act_list.

        * darwin_stop_world.c (GC_push_all_stacks, GC_stop_world,
        GC_start_world): Call vm_deallocate to free act_list. Fix from
        Bruce Mitchener.

From-SVN: r112867