And helper functions __nss_readline, __nss_readline_seek,
__nss_parse_line_result.
This consolidates common code for handling overlong lines and
parse files. Use the new functionality in internal_getent
in nss/nss_files/files-XXX.c.
Tested-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
