bug#37455: 27.0.50; insert-behind-hooks and insert-in-front-hooks in text properties do nothing when font-lock-mode is on

[Eli Zaretskii]

> From: 'Ihor Radchenko' <yantar92@gmail.com>
> Date: Thu, 19 Sep 2019 08:48:57 +0800
> 
> Expected behaviour:
> 
> According to the manual, adding insert-in-front-hooks or
> insert-behind-hooks text properties should trigger the functions listed
> in the hooks when the text is inserted in front/behind the text.
> 
> Observed behaviour:
> 
> The functions never run unless I type very fast (with my own config) or
> when font-lock-mode is enabled.

We have too many hooks, and they fight each other.  Recursively.

Should be fixed now on the master branch.  Thanks.