Description:
------------
Every ((65535*n)-1)th element in glob() and DirectoryIterator() appears twice. 

Values of glob() array are not unique.

Test script:
---------------
<?php

function foo($tmp_dir, $count){
  for($i = 1; $i <= $count; $i++){
    @mkdir($tmp_dir.'/'.$i, 0777, true);
  }

  $count_glob = count(glob($tmp_dir.'/*'), GLOB_ONLYDIR);

  $count_dir_iterator = 0;
  $dir = new \DirectoryIterator($tmp_dir);
  foreach($dir as $fileInfo){
    if($fileInfo->isDir() && !$fileInfo->isDot()){
      $count_dir_iterator++;
    }
  }
  return [$count_glob, $count_dir_iterator];
}

echo foo('d:/test', 65533)."\n"; // 65533
echo foo('d:/test', 65534)."\n"; // 65535
echo foo('d:/test', 131068)."\n"; // 131069
echo foo('d:/test', 131069)."\n"; // 131071