Incorrect values computed for literal array with fill-pointer 1 in compiled code

[Paul F. Dietz]

(defun bug222 ()
  (let* ((a (make-array '(10) :element-type '(unsigned-byte 62)
                              :fill-pointer 1
                              :initial-contents '(4 8 10 20 25 35 76 89 100 203)
                              ))
         (lam `(lambda (i) (aref ,a i)))
         (fn (compile nil lam)))
    (values (loop for i from 0 below 10
                  collect (aref a i))
            (loop for i from 0 below 10
                  collect (funcall fn i)))))

(bug222) ==>

(4 8 10 20 25 35 76 89 100 203)
(4 4 4 4 4 4 4 4 4 4)

This bug does not occur if the fill-pointer is instead initialized to 2.

x86-64, "2.3.7.147-e4b270bb5"