Message 285463 - Python tracker

1. _PyCFunction_FastCallKeywords() calls _PyStack_AsDict(), then calls _PyCFunction_FastCallDict().
2. _PyCFunction_FastCallDict() calls _Py_FastCall_FromArgs() when METH_FASTCALL.
3. _Py_FastCall_FromArgs() calls _PyStack_UnpackDict(), then calls fastcall().

Can you remove this _PyStack_AsDict() & _PyStack_UnpackDict() by creating shortcut in _PyCFunction_FastCallKeywords()?