Description:
------------
Working with RecursiveDirectoryIterator bring a weird order in differrent machines.

if I had a directory with two files:
test1.ext
test2.ext

in some installs the order will be
test1.ext
test2.ext

and in anothers will be
test2.ext
test1.ext

the main problem is that I can't trust in result, so the goal is iterator guarantee a certain order in all 


Reproduce code:
---------------
# you must create a 'test_data_fixtures' dir
# and put two files there test2.yml test1.yml

$dir = 'test_data_fixtures';
$it = new RecursiveDirectoryIterator($dir, RecursiveIteratorIterator::LEAVES_ONLY);                                                            
foreach ($it as $file) {
  echo "File: " . $file . "\n";
}

Expected result:
----------------
File: test_data_fixtures/test1.yml
File: test_data_fixtures/test2.yml

Actual result:
--------------
File: test_data_fixtures/test2.yml
File: test_data_fixtures/test1.yml