[Bug c/67854] Missing diagnostic for passing bool to va_arg

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67854

--- Comment #7 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Yeah, I know; I've already fixed the NULL case some time ago (though I'm not
sure if all the appropriate spots are fixed).