[fpc-pascal] Large file support

[Marco van de Voort]

In our previous episode, Mark Morgan Lloyd said:
> Could I have a reality check please: is there no fpLSeek64() for files 
> larger than 2Gb?

Afaik, there is no such posix calls. In the past, most linux temporarily had
some -64 calls while it left the main calls 32-bit to make transition
smoother, but nowadays it is all 64-bit?

What does writeln(sizeof(off_t));  print ?