destructuring-bind on an atom results in wrong error message

[Michael Fiano]

(defun foo ()
  (let ((bar 42))
    (destructuring-bind (&key baz) bar
      baz)))

; error while parsing arguments to NIL DESTRUCTURING-BIND:
; dotted keyword/value list: 42

The error message should be fixed, since 42 is not a dotted list.
The value is constant and destructuring-bind could emit a compile-time warning.
I believe destructuring-bind needs to be updated for the case when its second argument is constantp.

macro expansion:
(defun foo ()
  (let ((bar 42))
    (LET* ((#:G557 (SB-C::CHECK-DS-LIST/&KEY BAR 0 0 '(&KEY BAZ) #(:BAZ)))
           (#:G558 (SB-C::DS-GETF #:G557 ':BAZ))
           (BAZ
            (IF (NOT (EQL #:G558 0))
                (CAR (TRULY-THE CONS #:G558)))))
      BAZ)))

[Douglas Katzman (dougk)]

Changed the error message in https://sourceforge.net/p/sbcl/sbcl/ci/143d47eeca22fad26404f26101510d613bda20ad/

Not sure what "updated for the case when ... constantp" means - the macro works fine.
("could" and "needs to" are quite different claims).