[HAVE_CONFIG_H]: Include <config.h>.

[HAVE_CONFIG_H]: Include <config.h>.
[HAVE_SYS_PARAM_H || _LIBC]: Guard inclusion of <sys/param.h>.
Include <sys/stat.h>, not <include/sys/stat.h>, if !_LIBC.
[!_LIBC] (__chdir, __closedir, __fchdir, __getcwd, __opendir): Define.
[!_LIBC] (__readdir64, __tdestroy, __tfind, __tsearch): Define.
[!_LIBC] (internal_function, dirent64, MAX): Define.
(__set_errno): Define if not already defined.
(open_dir_stream): When FTW_CHDIR is enabled, invoke opendir on
the basename, not the entire file name.
(process_entry): When FTW_CHDIR is enabled, invoke XSTAT or LXSTAT on
the basename, not the entire file name.