Description:
------------
When iterating over generators sometimes yielded objects have extra references somewhere. I tried to simplify the test case as much has possible but almost same code in single file did not had this problem

Test script:
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https://github.com/GrandLTU/GeneratorTest

Expected result:
----------------
$ php bin/test.php
Object created 
Object created
Object destroyed 
Object destroyed 
int(0)
int(0)
Exit

Actual result:
--------------
$ php bin/test.php
Object created 
Object created 
int(2)
int(2)
Exit
Object destroyed 
Object destroyed