In Include/ucnhash.h I notice some integers and wonder if those should be Py_ssize_t. It looks like they are just names so they should be pretty short.
But in Objects/unicodeobject.c, I notice a bunch of ints and casts to int and wonder if they should be changed to Py_ssize_t/removed:
235: assert(length<INT_MAX); unicode->length = (int)length;
376, 404: int i;
1366: (seems like this could be a 64-bit value) int nneeded;
(i stopped at this point, there are probably more)
Modules/unicodedata.c (lots of ints, not sure if they are a problem)
494: isize = PyUnicode_GET_SIZE(input);