[fpc-pascal] Prevent full unit path in ppu files? together with -Ur

[Martin Frb]

On 12/04/2020 16:31, Martin wrote:
> When building packages for an installer, one uses -Ur.
>
> Yet (on Windows) I noted, that the ppu contain the full path to the 
> source file used to build that ppu.
>
> Not a major issue, but slightly awkward.
> - The files (ppu, and maybe sources) will be packed into an installer
> - The end user installs them to a patch of their choice. This is most 
> likely different from the build system.
>
> In the best case, the end users system has now links to none existing 
> files.
> In the worst case, the links point to a different installation, with 
> different versions of the files.
>
> Well probably no harm, since fpc will not recompile those files.
> Problematic maybe if other tools (like Lazarus) read that info from 
> the ppu.
>
> Therefore the question: Can that full path be prevented from getting 
> into the ppu (or any other file)?
>

Just digging a bit deeper, searching all files indicates that this full 
path is stored in *.fpm files