fix interpretation of defsetf lambda lists

[enometh]

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• lib/setf.lisp: (defsetf) use CCL::%DESTRUCTURE-LAMBDA-LIST instead of CCL::RENAME-LAMBDA-VARS to come up with a suitable setf expansion.

https://lists.clozure.com/pipermail/openmcl-devel/2020-September/012217.html

Currently CCL does not expand defsetf lambda lists of the form (defsetf get-foo (&key (add1 1) (add2 (+ add1 2))) (data) `(setq $foo (- ,data ,add1 ,add2))) (get-setf-expansion '(get-foo)) ;; => The value #:ADD1 is not of the expected type NUMBER.

WIP. This patch tries to rectify that. With this patch

(setf (get-foo) 10) ;; should return 6

The patch is for review and doesn't fix indentation and involved the use of of an unhygenic EXPRESSION symbol. This is to facilitate easy review.