run-tests.php and dynamic extension dependencies

Hi, 4 years ago, Derick proposed a patch to add an '--EXTENSIONS--' section in phpt files for extensions depending on another one (http://grokbase.com/t/php/php-internals/11bwptaj78/run-tests-php-and-dynamic-extension-dependencies). I don't know why, but it seems the patch was not commited. So, could someone explain how I can write and run phpt tests in an extension which depends on another dynamically loaded one ? Everything I tried so far except directly modifying the Makefile failed. And even modifying the Makefile is far from trivial. I tried to look at pdo drivers but, in practice, they don't need this because pdo is always compiled statically. They just use module dependencies for loading order. Thanks in advance François