Consolidate renameat Linux implementation

This patch consolidates the Linux renameat implementation on
sysdeps/unix/sysv/linux/renameat.c.  The renameat syscall was
deprecated at b0da6d44 for newer architectures, so using the
auto-generation list may generate wrappers that returns ENOSYS.

Current code try to use __NR_renameat and if it is not define
it uses __NR_renameat2.

Checked on x86_64 and aarch64.

	* sysdeps/unix/sysv/linux/renameat.c: New file.
	* sysdeps/unix/sysv/linux/syscalls.list: Remove renameat.

sysdeps/unix/sysv/linux/renameat.c

@@ -0,0 +1,32 @@
+/* Linux implementation for renameat function.
+   Copyright (C) 2016 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 <stdio.h>
+#include <fcntl.h>
+#include <sysdep.h>
+#include <errno.h>
+
+int
+renameat (int oldfd, const char *old, int newfd, const char *new)
+{
+#ifdef __NR_renameat
+  return INLINE_SYSCALL_CALL (renameat, oldfd, old, newfd, new);
+#else
+  return INLINE_SYSCALL_CALL (renameat2, oldfd, old, newfd, new, 0);
+#endif
+}