[fpc-pascal] cthreads

[Marco van de Voort]

In our previous episode, Mark Morgan Lloyd said:
> Going back to something less labour intensive, would it be possible to 
> have s directive which has the effect that if a procedure isn't 
> eliminated by smartlinking then the linker should warn if a specific 
> library hasn't been linked?

ELF binaries generally don't require to associate a symbol with a library
name to link, like on Windows.