Subject: bug#56682: Fix the long lines font locking related slowdowns

From: Gerd Möllmann <[email-masked]>
Date: Sat, 23 Jul 2022 17:01:02 +0200

And the new lottery numbers on the feature branch are:

Font-lock Scroll-bar Composition Output
------------------------------------------------------------
on	  on	     on		 GCs: 14 Elapsed time: 7.276626 seconds
on	  off	     on		 GCs: 1 Elapsed time: 5.363002 seconds
on	  off	     off	 GCs: 1 Elapsed time: 3.967520 seconds