* rt/Versions (librt): Export __mq_open_2@@GLIBC_2.7.

* rt/Versions (librt): Export __mq_open_2@@GLIBC_2.7.

	* rt/Makefile (headers): Add bits/mqueue2.h.
	* rt/mqueue.h: Include bits/mqueue2.h if -D_FORTIFY_SOURCE=2,
	optimizing with GCC and __va_arg_pack_len is defined.
	* rt/bits/mqueue2.h: New file.
	* rt/mq_open.c (__mq_open): Renamed from mq_open.
	(mq_open): New strong_alias.
	(__mq_open_2): New function.
	* sysdeps/unix/sysv/linux/mq_open.c (__mq_open): Renamed from mq_open.
	(mq_open): New strong_alias.
	(__mq_open_2): New function.
	* debug/Versions (libc): Export __fortify_fail@@GLIBC_PRIVATE.
	* Versions.def (librt): Add GLIBC_2.7 version.
	* debug/fortify_fail.c (__fortify_fail): Add libc_hidden_def.
	* include/stdio.h (__fortify_fail): Add libc_hidden_proto.

	* misc/sys/cdefs.h (__errordecl, __va_arg_pack_len): Define.
	* io/fcntl.h: Include bits/fcntl2.h when __va_arg_pack_len
	is defined rather than when not C++.
	* io/bits/fcntl2.h (__open_alias, __open64_alias, __openat_alias,
	__openat64_alias): New redirects.
	(__open_too_many_args, __open_missing_mode, __open64_too_many_args,
	__open64_missing_mode, __openat_too_many_args, __openat_missing_mode,
	__openat64_too_many_args, __openat64_missing_mode): New __errordecls.
	(open, open64, openat, openat64): Rewrite as __extern_always_inline
	functions instead of function-like macros.