Description:
------------
If we set an environment variable through Apache (or Nginx), the variable will be available in "$_ENV" and "$_SERVER". 

Unfortunately, if we set an environment variable through the built-in server, the variable will only be available in "$_ENV" (not in $_SERVER).

See the original issue related: https://github.com/symfony/symfony/issues/10208

Test script:
---------------
# test.php
<?php
var_dump($_ENV['FOO']);
var_dump($_SERVER['FOO']);

# bash
export FOO="bar"
php -d variables_order=EGPCS -S 0.0.0.0:8000 -t . test.php


Expected result:
----------------
string 'bar' (length=3)
string 'bar' (length=3)

Actual result:
--------------
string 'bar' (length=3)
Notice: Undefined index: FOO