Implement an internal version of __access called __access_noerrno that
avoids setting errno. This is useful to check accessibility of files
very early on in process startup i.e. before TLS setup. This allows
tunables to replace MALLOC_CHECK_ safely (i.e. check existence of
/etc/suid-debug to enable/disable MALLOC_CHECK) and at the same time
initialize very early so that it can override IFUNCs.
Checked on x86_64.
* hurd/hurd.h (__hurd_fail_noerrno): New function.
* include/unistd.h [IS_IN (rtld) || !defined SHARED]: Declare
__access_noerrno.
* io/access.c (__access_noerrno): New function.
* sysdeps/mach/hurd/access.c (hurd_fail_seterrno): New function.
(hurd_fail_seterrno): Likewise.
(access_common): Likewise.
(__access_noerrno): Likewise.
* sysdeps/nacl/access.c (__access_noerrno): Likewise.
* sysdeps/unix/sysv/linux/access.c (__access_noerrno): Likewise.
* sysdeps/nacl/nacl-interfaces.h (NACL_CALL_NOERRNO): New
macro.
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