bug#54382: 28.0.92; --with-x-toolkit=no leads to "FALLTHROUGH undefined" in Activate.c

[Po Lu]

Paul Eggert <eggert@cs.ucla.edu> writes:

>  #include <config.h>
>  
> +#include <attribute.h>
> +
>  /* Avoid warnings about redefining NULL by including <stdio.h> first;
>     the other file which wants to define it (<stddef.h> on Ultrix
>     systems) can deal if NULL is already defined, but <stdio.h> can't.  */

I would rather not bring any more includes into oldXMenu, so maybe keep
it as-is?

Thanks.