Description:
------------
PHP7 has a bug with post-incrementing and/or decrementing variables returned by reference via magic getters.

See: http://3v4l.org/mvNGC

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

class A {

    private $foo = 0;

    public function &__get($foo){ return $this->foo; }

}

$a = new A;
echo $a->f++;
echo $a->f++;
echo $a->f++;

Expected result:
----------------
012

Actual result:
--------------
112