* benchmark/bm_vm3_thread_mutex[1-3].rb: added 3 benchmarks.
1: one thread with one mutex (no contention).
2: two threads with one mutex (contention).
3: 1000 threads with one mutex (huge number of contention)
Abobe removed benchmark was type 3.
Therefore, this commit adds type 1 and 2 benchmark.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@32020 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
ko1