bug#50970: 29.0.50; Italics cause fill column indicator misalignment

[Carlos Pita]

Well, I’ve done literally thousands of restarts in different combinations of 
emacs versions, extensions, etc. Each new combination was tested in at least 
100 restarts. This is what I can say:

* It never happened with 27.2 in any combination.
* With a minimal configuration it still happens in 28, but at a very low 
frequency (maybe < 1/100).
* The same after recompiling all my extensions.
* It never happened after removing the elpa directory altogether.
* Having global company mode enabled is what raises the frequency (> 1/10).

My highlights on the above (taking into account that “never" means “not yet 
seen”):

* The problem is likely in 28, not in 27.2.
* I would say it’s always waiting there but some setups make it more frequent.
* Enabling company is the easiest way to (probabilistic) reproducibility I’ve 
found.

BTW, I now feel authorized to say that startup time has improved a lot, any 
specific optimization there?