fastcall_macros.patch:

* Rename _PyObject_FastCall() to _PyObject_FastCallDict()
* Add _PyObject_FastCall(func, args, nargs) macro
* Add _PyObject_CallArg1(func, arg) macro
* Add _PyObject_CallNoArg(func) macro

The 3 new macros call _PyObject_FastCallDict().

Statistics on calls to these functions and macros:

* _PyObject_CallNoArg: 11
* _PyObject_CallArg1: 8
* _PyObject_FastCall: 5
* _PyObject_FastCallDict: 0   (the function doesn't work yet, it's the purpose of this issue, so it's expected that it's unused yet ;-))

_PyObject_CallNoArg() and _PyObject_CallArg1() are much more common and the more complex format _PyObject_FastCall() format (more than 1 argument). I like having macros with a simple prototype.

--

The C API has a wide choice of functions to call a function, but I still want to add  _PyObject_CallNoArg() and _PyObject_CallArg1() to get the best performances (avoid layers before reaching the final _PyObject_FastCallDict) and have a simple and well defined prototype for the most common function calls.

kwargs:

* PyObject_Call(): root of all call functions in Python 3.5
* PyEval_CallObjectWithKeywords(func, args, kwargs) -> PyObject_Call()

args:

* PyEval_CallObject(func, args)
* PyObject_CallObject(func, args) -> PyEval_CallObjectWithKeywords()

vargs:

* PyObject_CallFunctionObjArgs(func, ...) -> PyObject_Call()

format:

* PyObject_CallFunction(func, format, ...) -> PyObject_Call()
* PyObject_CallMethod(func, method, format, ...) -> PyObject_Call()
* _PyObject_CallMethodId(func, method_id, format, ...) -> PyObject_Call()
* PyEval_CallFunction(func, format, ...) -> PyEval_CallObject()
* PyEval_CallMethod(func, method, format, ...) -> PyEval_CallObject()

Fast call:

* _PyObject_CallNoArg(func) -> _PyObject_FastCallDict()
* _PyObject_CallArg1(func, arg) -> _PyObject_FastCallDict()
* _PyObject_FastCall(func, arg) -> _PyObject_FastCallDict()