bug#26073: workaround

[Noam Postavsky]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

> I just installed a patch into `master` which should hopefully fix this
> problem without introducing new ones.

The examples given still fail on current master.

(require 'generator)
(setq lexical-binding t) ; for easier *scratch* evaluation
(iter-do (y (funcall (iter-lambda (x)
                       (dolist (it x)
                         (let ((y (mapcar (lambda (it) (- it)) it)))
                           (iter-yield y))))
                     '((1 2) ( 3 4))))
  (print y)) ;=> Lisp error: (wrong-type-argument number-or-marker-p (1 2))

(iter-next (funcall (iter-lambda ()
                      (let ((it 1))
                        (iter-yield (funcall (lambda (it) (- it)) (1+ it))))))) 
 ;=> -1