Further refinements of ptsname_r(3) interface:

- Hide ptsname_r under __BSD_VISIBLE for now as the specification
   is not finalized at this time.
 - Keep Symbol.map sorted.
 - Avoid the interposing of ptsname_r(3) from an user application
   from breaking ptsname(3) by making the implementation a static
   method and call the static function from ptsname(3) instead.

Reported by:	kib
Reviewed by:	kib, jilles
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D26845

include/stdlib.h

@@ -211,7 +211,6 @@ double	 drand48(void);
 double	 erand48(unsigned short[3]);
 /* char	*fcvt(double, int, int * __restrict, int * __restrict); */
 /* char	*gcvt(double, int, int * __restrict, int * __restrict); */
-int	 grantpt(int);
 char	*initstate(unsigned int, char *, size_t);
 long	 jrand48(unsigned short[3]);
 char	*l64a(long);
@@ -223,9 +222,6 @@ char	*mktemp(char *);
 #endif
 long	 mrand48(void);
 long	 nrand48(unsigned short[3]);
-int	 posix_openpt(int);
-char	*ptsname(int);
-int	 ptsname_r(int, char *, size_t);
 int	 putenv(char *);
 long	 random(void);
 unsigned short
@@ -233,8 +229,18 @@ unsigned short
 char	*setstate(/* const */ char *);
 void	 srand48(long);
 void	 srandom(unsigned int);
+#endif /* __XSI_VISIBLE */
+
+#if __XSI_VISIBLE
+int	 grantpt(int);
+int	 posix_openpt(int);
+char	*ptsname(int);
 int	 unlockpt(int);
 #endif /* __XSI_VISIBLE */
+#if __BSD_VISIBLE
+/* ptsname_r will be included in POSIX issue 8 */
+int	 ptsname_r(int, char *, size_t);
+#endif
 
 #if __BSD_VISIBLE
 extern const char *malloc_conf;