Hi Jeff,

Ah, I think I understand now what is going on.  The special-casing for
PyPy should not be needed at all, but when I removed it, I get
assertion failures.  Now I get the reason---yes, it is yet another bug
inside cpyext, caused by yet another access pattern of "PyObject *"
that is somehow unusual but should be allowed.

I can try to fix it inside cpyext, and then the "if IS_PYPY" cases in
proxy.pxi should be removed.  (I'm unsure if it is easy to change them
to "if the version of PyPy is <= 2.6.1"...)