Symfony version(s) affected: symfony/doctrine-bridge 4.4.19 - 5.2.2

Description
When Doctrine relationships with Abstract Classes and Interfaces are used, Symfony crashes with an 137 exit code (out of memory).

This problem is observed since the 23d6921 commit.

How to reproduce

• Use Doctrine relationships with Abstract Classes and Interfaces
• Use Doctrine (eg: php bin/console doctrine:schema:validate)

Tested with PHP 7.2.34, 7.3.26, 7.4.14 and 8.0.1