ptsname_r: new module For now, this replacement focuses solely on compilation compatibility, and assumes that isatty() and ttyname_r() work on a master side pty; if this assumption fails, or if thread-safety is also required, then a later patch can follow the lead of strerror_r.c in wrapping the system ptsname() with a lock. * modules/ptsname_r: New module. * m4/ptsname_r.m4 (gl_FUNC_PTSNAME_R): New file. * lib/ptsname.c (__ptsname_r): Split... * lib/ptsname_r.c: ...into new file. * m4/stdlib_h.m4 (gl_STDLIB_H): Check for decl. (gl_STDLIB_H_DEFAULTS): Set witness defaults. * modules/stdlib (Makefile.am): Substitute witnesses. * lib/stdlib.in.h (ptsname_r): Declare it. * doc/glibc-functions/ptsname_r.texi (ptsname_r): Document it. * MODULES.html.sh (Misc): Likewise. * modules/ptsname (Depends-on): Alter dependency. * doc/posix-functions/ptsname.texi (ptsname): Mention new module. Signed-off-by: Eric Blake <eblake@redhat.com>