[fpc-pascal] Syserrormessage, parameter data type

[Marco van de Voort]

In our previous episode, Michael Van Canneyt said:
> > current situation
> > it *never* works correctly (not even for Linux).
> 
> That is why we need an opaque type which will probably be used in more than one call.
> It needs to be investigated, hence the bugreport is needed.

(to Joergen:) don't forget to attach the code that actually causes a problem
to the bugreport, so we can test if it is resolved on Windows.