bug#37633: Column part interpreted wrong in compilation mode

[Eli Zaretskii]

> Cc: anton@mips.complang.tuwien.ac.at
> Date: Sat, 05 Oct 2019 13:12:34 +0200
> From: Bernd Paysan via "Bug reports for GNU Emacs,
>  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
> 
> Suggested solution: Use byte-to-position to calculate the position in 
> compilation-move-to-column.

This only works in UTF-8 locales, and is not 100% even there, so it
isn't the right solution.