In ANSI mode, we declare unvis(3) as
   	int unvis(char *, char, int *, int);
   but the actual library declaration is
   	int unvis(a, b, c, d)
   		char *a;
   		char b;
   		int *c;
   		int d;

in my own code, i use something similar to __P, and for the functions
that take a short or a char, i provide to definitions of the function:

int
#ifdef __STDC__
foo(char baz, short bop)
#else
foo(baz, bop)
	char baz;
	short hop;
#endif

to deal with this lossage.


as far as i was able to tell when i implemented this, it's the only
way to be correct *and* compatible.