Move duplicated rnew cloning from apr_ap_sub_req_lookup_*() functions,
  and add an ap_sub_req_lookup_dirent() to create a subrequest from the
  results of an apr_dir_read() for mod_negotiation and mod_autoindex.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@89437 13f79535-47bb-0310-9956-ffa450edef68