Description:
------------
PHP 7.2.17-0ubuntu0.18.04.1 (cli) (built: Apr 18 2019 14:12:38) ( NTS )

When using `move_uploaded_file` with a stream wrapper url as destination, the return value of the method `stream_flush` is ignored. The function `move_uploaded_file` always returns true, even if `stream_flush` returns false.

Test script:
---------------
class MyStreamWrapper
{
    ...

    public function stream_write($data)
    {
        return 1;
    }

    public function stream_flush()
    {
        return false;
    }

    ...
}

stream_wrapper_register('my-wrapper', \MyStreamWrapper::class, 0);
$res = move_uploaded_file($_FILES['uploaded_file']['tmp_name'], 'my-wrapper://' . basename($_FILES['uploaded_file']['name']));
stream_wrapper_unregister('my-wrapper');
echo $res ? 'true' : 'false';



Expected result:
----------------
false

Actual result:
--------------
true