Now with the latest patch, and under a 64-bit system (the same one
actually, but with a 64-bit distro):

* pybench is roughly 2% slower 
* timeit -s "a=100000000;b=777777" "a//b"
- before: 0.563 usec per loop
- after: 0.226 usec per loop
* timeit -s "a=100000000;b=777777" "a*b"
- before: 0.179 usec per loop
- after: 0.131 usec per loop
* timeit -s "a=100000000;b=777777" "a+b"
- before: 0.174 usec per loop
- after: 0.134 usec per loop