bug#33314: 27.0.50; wrong compiler warning

[Andreas Röhler]

Get a compiler Warning: Unused lexical variable ‘regexp’

WRT a form like below:

(defun foo (regexp &optional something)
  "..."
  (unless (bobp)
    (when (empty-line-p) (skip-chars-backward " \t\r\n\f"))
    (let* ((orig (point))
	   (regexpvalue (if (eq regexp 'py-clause-re) (symbol-value 
'py-extended-block-or-clause-re) (symbol-value regexp)))
...

;;

As visible, regexp is evaluated in last clause.

Thanks,
Andreas
GNU Emacs 27.0.50 (build 1, i686-pc-linux-gnu, GTK+ Version 3.14.5) of 
2018-10-13