[Reduction] #689: Long pointer+scalar addition

This file has been lying around there for almost three months now, because I
initially couldn't describe its functionality...
[Reduction] #690: farcalloc
[Reduction] #691: farcoreleft
[Reduction] #692: coreleft
[Reduction] #693: scanner
[Reduction] #694: scanf
[Reduction] #695-696: User entry points for read() and write()

That's it, segment 0 cleared out in all executables of TH01! Only missing that
last floating-point slice now...