Type format for CL.

[mariari]

It would be nice if we could request type information from alucard terms in CL functions

(defun reshape (array new-element-type) 
  (with-requested-type array array-type
    (match array-type
      ((array length type)
       (coerce array
              (array
               (* length
                  (cl:- (element-size element-type) (element-size type)))
               new-element-type)))))

with that this code can be made. Meaning that we can offer a more safe way to reshape an array form CL. rather than just doing the math in our head.