Constant folding errors from make-double-double-float

[Raymond Toy]

Compiling

(defun zot ()
  (kernel:make-double-double-float least-positive-normalized-double-float 0d0))

causes several warnings like:

;   (KERNEL:MAKE-DOUBLE-DOUBLE-FLOAT LEAST-POSITIVE-NORMALIZED-DOUBLE-FLOAT
;                                    0.0d0)
; --> BLOCK IF OR LET IF OR FLOAT-NAN-P BLOCK KERNEL::NUMBER-DISPATCH 
; --> BLOCK TAGBODY RETURN-FROM TYPECASE LET COND IF PROGN LET 
; ==>
;   (KERNEL:SINGLE-FLOAT-BITS KERNEL::X)
; Warning: Lisp error during constant folding:
; Type-error in KERNEL::OBJECT-NOT-SINGLE-FLOAT-ERROR-HANDLER:
;    2.2250738585072014d-308 is not of type SINGLE-FLOAT

Looks like it's from float-nan-p.

The result is correct, but the warnings are annoying.