stdio.h, VAX versus SUN

[Jim Franklin]

In BSD 4.2, file /usr/include/stdio.h contains the following
declaration for sprintf():

#ifdef vax
char	*sprintf();		/* too painful to do right */
#endif

The same lines are present in /usr/include/stdio.h on our SUN 4.2
systems,  where they make even less sense.  Since "vax" is not #defined
there, sprintf() is never declared to be char *.  This causes
subsequent problems with lint().

Can anyone tell me why the #ifdef vax lines are present on either system
(VAX or SUN)?