Description:
------------
Server: docker ubuntu14.04 
php-fpm version:7.0.15 and 7.0.20
Nginx: 1.4.6

getcwd() incorrect output in register_shutdown_function()

getcwd() returns wrong directory in register_shutdown_function(), only happens when using php-fpm or cgi. Bug not found in cli mode. 

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

echo "Expected:" . getcwd() . "<br>";

register_shutdown_function(function () {
    echo "In shutdown function:" . getcwd() . "<br>";
});


// Output:
// Expected:/var/www/html/test
// In shutdown function:/

Expected result:
----------------
Expected:/var/www/html/test
In shutdown function:/var/www/html/test

Actual result:
--------------
Expected:/var/www/html/test
In shutdown function:/