[Bug c/61898] Variadic functions accept va_list without warning

[andi-gcc at firstfloor dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61898

--- Comment #4 from Andi Kleen <andi-gcc at firstfloor dot org> ---
The patch has several issues (making it  currently fail bootstrap):
- it warns for vfprintf too (fixed)
- on i386 it gets confused between va_list * and char *, so something like

char *format;
char buf[100];

printf(format, buf)

warns too because the underlying types are the same.
Not sure about a good solution for this, need a new type attribute?