bug#41278: 27.0.91; incorrect U+203E OVERLINE alignment with Fantasque Sans Mono

[Eli Zaretskii]

> From: Vincent Lefevre <vincent@vinc17.net>
> Date: Thu, 14 May 2020 21:41:13 +0200
> 
> On the following text file:
> 
> underline
> ‾‾‾‾‾‾‾‾‾
> 
> (where ‾ is U+203E OVERLINE), the command
> 
>   emacs -Q -fn "Fantasque Sans Mono" text
> 
> shows an incorrect alignment (see attached screenshot).

AFAICT, that font doesn't have a glyph for U+203E, so Emacs is
probably using some other font, which has a different width.  (I
looked in version 1.8.0 of the font, not 1.7.2.)