Move some things from sysdeps/unix to sysdeps/posix.

sysdeps/posix/mkfifo.c

@@ -0,0 +1,29 @@
+/* Copyright (C) 1991, 1996, 1997 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <stddef.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+/* Create a named pipe (FIFO) named PATH with protections MODE.  */
+int
+mkfifo (const char *path, mode_t mode)
+{
+  dev_t dev = 0;
+  return __xmknod (_MKNOD_VER, path, mode | S_IFIFO, &dev);
+}