rather than either constant-folding or manipulating NIL-VALUE or
NULL-TN directly.
--------------------------------------------------------------------------------
-#19
- (let ((dx (if (foo)
- (list x)
- (list y z))))
- (declare (dynamic-extent dx))
- ...)
-
-DX is not allocated on stack.
---------------------------------------------------------------------------------
#20
(defun-with-dx foo (x)
(flet ((make (x)