bug#46468: 28.0.50; difficult to find undisplayable characters

[joakim]

- It's possible to avoid the problem by using this cookie in the
- problematic files:

-*- coding: utf-8 -*-

- Following Andreas suggestion I created a small search function:
(defun search-bad ()
    (interactive)
  (search-forward-regexp   "[\200-\377]"))

The function didnt really help me solve my problem, but the
aforementioned cookie did.

I think this is kind of clunky, but if nobody else has this problem,
this solution is good enough for me and the bug can be closed.
-- 
Joakim Verona
joakim@verona.se