* lisp/progmodes/cperl-mode.el (cperl--package-regexp):
Avoid double repetition; cperl--ws-or-comment-regexp is already
repeated with 1+.
* test/lisp/textmodes/dns-mode-tests.el
(dns-mode-tests-dns-mode-soa-increment-serial): Escape literal '$'.
* test/lisp/emacs-lisp/rx-tests.el (rx-regexp): Modify test to not
trigger a linting warning while retaining its testing power.