Some minor cleanups in PyLong_FromLong:  - fast path wasn't being properly taken for negative ints;    thanks Victor Stinner for pointing this out.  - use Py_SAFE_DOWNCAST instead of direct casting to digit    (it's safer, especially if we ever consider moving to 30-bit    digits)  - cleaner way to write negation
Some minor cleanups in PyLong_FromLong:
 - fast path wasn't being properly taken for negative ints;
   thanks Victor Stinner for pointing this out.
 - use Py_SAFE_DOWNCAST instead of direct casting to digit
   (it's safer, especially if we ever consider moving to 30-bit
   digits)
 - cleaner way to write negation

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator