test: add test case for process.dlopen with undefined

PR-URL: https://github.com/nodejs/node/pull/17343


Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Yuta Hiroto <hello@about-hiroppy.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Daijiro Wachi <daijiro.wachi@gmail.com>