; cperl-mode.el: Remove functions using mode-compile.el

; cperl-mode.el: Remove functions using mode-compile.el

mode-compile.el is no longer available from any maintained repository,
its archived version does not work since Emacs 27.  The menu options
tested for availability of mode-compile and therefore were disabled,
the function was not documented.

* lisp/progmodes/cperl-mode.el (cperl-tips): Remove reference to
mode-compile.el.
(cperl-menu): Remove defunct entries requiring mode-compile.
(cperl-check-syntax): Remove function.
(cperl-extra-perl-args): Remove user option only used by cperl-check-syntax.