Message 349893 - Python tracker

I couldn't reproduce entire test, as wsdiff script is rather large, but here's the simplified version. If Popen is used more often, difference is much more significant.

# Using workaround
$ python3.5 ~/tmp/1.py 1 
10.780487537384033
# Without workaround
$ python3.5 ~/tmp/1.py
13.347045660018921
# Using python2.7
$ python2.7 ~/tmp/1.py
9.83385586739