While hacking on CPython I noticed a couple of attributes that were
there strictly for backwards compatibility with ancient modules or pure
mistakes.  They are:
  _hashlib.hash.digestsize
  pwd.struct_pwent
  _sha224.digestsize
  _sha256.digestsize
  _sha384.digestsize
  _sha512.digestsize

None of these are part of the documented interface, and all of them are
redundant with documented interfaces.  I suggest that they can all go.

The attached patch removes all of the above.  With the patch applied
Python passes all expected unit tests.