[newlib-cygwin] grp.h: use __BSD_VISIBLE and __XSI_VISIBLE guards

[Yaakov Selkowitz <yselkowitz@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=a710c89dcb160eef714a272cc7610ed697c17369

commit a710c89dcb160eef714a272cc7610ed697c17369
Author: Yaakov Selkowitz <yselkowi@redhat.com>
Date:   Thu Jan 28 15:39:02 2016 -0600

    grp.h: use __BSD_VISIBLE and __XSI_VISIBLE guards
    
    This fixes the build of krb5 and other packages on Cygwin.
    
    	* libc/include/grp.h: Use __BSD_VISIBLE and __XSI_VISIBLE guards.
    
    Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>

Diff:
---
 newlib/libc/include/grp.h | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/newlib/libc/include/grp.h b/newlib/libc/include/grp.h
index c3a5a67..145e4ee 100644
--- a/newlib/libc/include/grp.h
+++ b/newlib/libc/include/grp.h
@@ -71,21 +71,19 @@ int		 getgrnam_r (const char *, struct group *,
 			char *, size_t, struct group **);
 int		 getgrgid_r (gid_t, struct group *,
 			char *, size_t, struct group **);
-#ifndef _POSIX_SOURCE
+#if __BSD_VISIBLE || __XSI_VISIBLE >= 500
 struct group	*getgrent (void);
 void		 setgrent (void);
 void		 endgrent (void);
-#ifndef __CYGWIN__
-void		 setgrfile (const char *);
-#endif /* !__CYGWIN__ */
-#ifndef _XOPEN_SOURCE
+#endif /* __BSD_VISIBLE || __XSI_VISIBLE >= 500 */
+#if __BSD_VISIBLE
 #ifndef __CYGWIN__
 char		*group_from_gid (gid_t, int);
+void		 setgrfile (const char *);
 int		 setgroupent (int);
 #endif /* !__CYGWIN__ */
 int		 initgroups (const char *, gid_t);
-#endif /* !_XOPEN_SOURCE */
-#endif /* !_POSIX_SOURCE */
+#endif /* __BSD_VISIBLE */
 #endif /* !__INSIDE_CYGWIN__ */
 
 #ifdef __cplusplus