invalid IGNORE/IGNORABLE declaration handling

[ichimal]

For current code which closing previous issue #2, there is an new problem around IGNORE/IGNORABLE declaration.

e.g.

    (local-function fun ((v1 ...) (v2 ...) ... (vk ...) vn)
      (declare (type fixnum v1 v2 ... vk) (ignore vn))
      ... )

above code will be expanded to below;

    (labels ((fun (#1=#:G1 #2=#:G2 ... #k=#:Gk #n=#:Gn)
               (declare (type fixnum #1# #2# ... #k#)
                        (ignore #n#) )
               (block fun
                 (tagbody #s=#:start-tag
                   (let ((v1 #1#) (v2 #2#) ... (vk #k#)
                         (vn #n#) )
                     (declare (type fixnum v1 v2 ... vk) (ignore vn))
                     ... )))))
      (fun ...) )

:Gn is declared as IGNORE, but it will be used as initial value of a following LET variable vn.

Is #:Gn declared as IGNORABLE?
Should vn be removed from internal LET and forbid to use vn?