Description:
------------
arrow function and  anonymous functions  should be garbage collect ,but it seems  be the full  life cycle  

it may relative with this 

https://github.com/php/php-src/blob/f3efb9e3fb30fa307e0913e888fb2859cec8209a/Zend/zend_compile.c#L6271 

Test script:
---------------
// file1.php
<?php
for ($i = 0; $i < 1000000; $i++)
{
                        require('file2.php');
}
// file2.php

<?php
$fn1 = fn($x) => $x + $y;


above wil oom
---------
below will not  oom 

// file3.php
<?php
for ($i = 0; $i < 1000000; $i++)
{
$fn1 = fn($x) => $x + $y;
}






Expected result:
----------------
not  report fatal error

Actual result:
--------------
Fatal error: Allowed memory size of 134217728 bytes exhausted at /root/php-src/Zend/zend_hash.c:149 (tried to allocate 384 bytes) in /home/dinosaur/test/php746/bin/file2.php on line 2