Description:
------------
As description at
http://php.net/manual/en/migration70.incompatible.php
The "Array ordering when elements are automatically created during by reference assignments has changed" is written.
And there is no other description about array ordering in
http://php.net/manual/en/migration71.incompatible.php
But, when I have confirmed the result, I saw that the output of php5.6.21 and php7.1.0RC3 are same.

I think that it is bug of PHP7.1.0RC3, but please confirm it is a bug or not.
Thank you.



Test script:
---------------
1.
php56.exe -r "$array = []; $array['a'] =& $array['b']; $array['b'] = 1; var_dump($array);"
Output:
array(2) {
  ["b"]=>
  &int(1)
  ["a"]=>
  &int(1)
}

2. // php7.0.6
php70.exe -r "$array = []; $array['a'] =& $array['b']; $array['b'] = 1; var_dump($array);"
Output:
array(2) {
  ["a"]=>
  &int(1)
  ["b"]=>
  &int(1)
}

3.
php71.exe -r "$array = []; $array['a'] =& $array['b']; $array['b'] = 1; var_dump($array);"
Output:
array(2) {
  ["b"]=>
  &int(1)
  ["a"]=>
  &int(1)
}



Expected result:
----------------
When executing this script
3.
php71.exe -r "$array = []; $array['a'] =& $array['b']; $array['b'] = 1; var_dump($array);"

The output will be same the output of php7.0.6
array(2) {
  ["a"]=>
  &int(1)
  ["b"]=>
  &int(1)
}