Update bytebench-3.1 to unixbench-4.1.0, based on patches submitted
by SHIMAOKA Shunsuke, with some modifications to the Makefile by me.
The bytebench port was repo-copied to unixbench, before, to preserve
its history.
Submitted by: SHIMAOKA Shunsuke (shimaoka at st dot tutrp dot tut dot ac dot jp)