Source changes for compilation

These are the commits from
https://github.com/ahgamut/cpython/tree/cosmo_py36 squashed for
simplicity.

Also included is the pyconfig.h used for compilation. The pyconfig.h has
to be changed manually in case Cosmopolitan gets new features.

third_party/python/Lib/locale.py

@@ -625,7 +625,7 @@ else:
             res = getdefaultlocale()[1]
             if res is None:
                 # LANG not set, default conservatively to ASCII
-                res = 'ascii'
+                res = 'utf-8'
             return res
     else:
         def getpreferredencoding(do_setlocale = True):