bug#61962: 30.0.50; New trouble with symbols with positions

[Eli Zaretskii]

> From: Michael Heerdegen <michael_heerdegen@web.de>
> Date: Sat, 04 Mar 2023 17:18:43 +0100
> 
> since a couple of days, maybe around a week, master builds bug me with
> symbols with positions again.
> 
> Here is a recipe for emacs -Q (dunno, there may be much simpler and
> shorter recipes, didn't try):
> 
> Save this into a file:
> 
> ;; -*- lexical-binding: t -*-
> 
> (cl-defstruct teststruct "Doc" xxx)
> 
> (defun test ()
>   (let ((val (make-teststruct :xxx 20)))
>     (pcase val
>       ((and (pred cl-struct-p)
>             (let class-name (type-of val)))
>        (when class-name
>          (ignore-errors
>            (mapcar #'cl--slot-descriptor-name
>                    (cl--class-slots
>                     (cl-find-class class-name)))))))))
> 
> Visit and M-x eval-buffer.  M-: (test) yields xxx as expected.
> 
> But now compile (C-c C-b) and M-: (test) unexpectedly (I guess?)
> yields (#<symbol xxx at 63>), a symbol with position.

Adding Alan and Mattias.