bug#37633: Column part interpreted wrong in compilation mode

[Eli Zaretskii]

> From: Bernd Paysan <bernd@net2o.de>
> Cc: 37633@debbugs.gnu.org, anton@mips.complang.tuwien.ac.at
> Date: Sat, 05 Oct 2019 20:54:38 +0200
> 
> > We cannot use 'exact' here because there's no file per se: we only
> > have the compiler output.  We must use 'approximate'.
> 
> The buffer that matters is not the compiler output, it's the buffer of the 
> source code.

But the column numbers are counted in the compiler output, and no one
said that the compiler output must be encoded the same as the source
file.