After r75467, which changed test_imp and test_import to use CleanImport,
the various pickle tests fail (all in the same common test, I believe).
 The error looks like this:

Traceback (most recent call last):
  File "/home/rdmurray/python/trunk/Lib/test/pickletester.py", line 623,
in test_structseq
    s = self.dumps(t, proto)
  File "/home/rdmurray/python/trunk/Lib/test/test_pickle.py", line 33,
in dumps
    p.dump(arg)
  File "/home/rdmurray/python/trunk/Lib/pickle.py", line 224, in dump
    self.save(obj)
  File "/home/rdmurray/python/trunk/Lib/pickle.py", line 331, in save
    self.save_reduce(obj=obj, *rv)
  File "/home/rdmurray/python/trunk/Lib/pickle.py", line 400, in save_reduce
    save(func)
  File "/home/rdmurray/python/trunk/Lib/pickle.py", line 286, in save
    f(self, obj) # Call unbound method with explicit self
  File "/home/rdmurray/python/trunk/Lib/pickle.py", line 753, in save_global
    (obj, module, name))
PicklingError: Can't pickle <function _make_stat_result at 0xb7a09494>:
it's not the same object as os._make_stat_result

I don't have enough pickle-foo to understand what it is trying to do
here or what about CleanImport is messing it up.