[fpc-pascal] detect CPU cores

[Marco van de Voort]

In our previous episode, Sven Barth said:
> FPC 2.7.1 has TThread.ProcessorCount (it's a class property, so no instance
> needed) or System.CpuCount (ProcessorCount uses this). It's not yet
> implemented though for any system :/

I ran it to test if it made a difference between cores and hyperthreading,
but didn't even get that far, on Windows it seems to always return 1.