Optimize location_walk.  We build an array of incremental matches, and
  on attempting a subreq/redirect or simply a second pass, and for each
  match in series, if the section is a match,  we reuse the merge result
  for that section.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@90925 13f79535-47bb-0310-9956-ffa450edef68