lib: fix a few minor issues flagged by lgtm

* Confusing (but correct) regex using `A-z` character range by
  accident
* Add the status argument to afterShutdown

PR-URL: https://github.com/nodejs/node/pull/25873


Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Sam Roberts <vieuxtech@gmail.com>