Put __Pyx_PyMethod_New directly in the tp_descr_get slot (GH-3116)

Minor cleanup regarding __Pyx_PyMethod_New

Cython/Utility/CythonFunction.c

@@ -74,7 +74,7 @@ static int __pyx_CyFunction_init(void);
 //////////////////// CythonFunction ////////////////////
 //@substitute: naming
 //@requires: CommonStructures.c::FetchCommonType
-////@requires: ObjectHandling.c::PyObjectGetAttrStr
+//@requires: ObjectHandling.c::PyMethodNew
 
 #include <structmember.h>
 
@@ -550,11 +550,6 @@ static int __Pyx_CyFunction_traverse(__pyx_CyFunctionObject *m, visitproc visit,
     return 0;
 }
 
-static PyObject *__Pyx_CyFunction_descr_get(PyObject *func, PyObject *obj, PyObject *type)
-{
-    return __Pyx_PyMethod_New(func, obj, type);
-}
-
 static PyObject*
 __Pyx_CyFunction_repr(__pyx_CyFunctionObject *op)
 {
@@ -701,7 +696,7 @@ static PyTypeObject __pyx_CyFunctionType_type = {
     __pyx_CyFunction_getsets,           /*tp_getset*/
     0,                                  /*tp_base*/
     0,                                  /*tp_dict*/
-    __Pyx_CyFunction_descr_get,         /*tp_descr_get*/
+    __Pyx_PyMethod_New,                 /*tp_descr_get*/
     0,                                  /*tp_descr_set*/
     offsetof(__pyx_CyFunctionObject, func_dict),/*tp_dictoffset*/
     0,                                  /*tp_init*/

Cython/Utility/ModuleSetupCode.c

@@ -705,12 +705,6 @@ static CYTHON_INLINE PyObject * __Pyx_PyDict_GetItemStrWithError(PyObject *dict,
   #define __Pyx_PyInt_AsHash_t   __Pyx_PyIndex_AsSsize_t
 #endif
 
-#if PY_MAJOR_VERSION >= 3
-  #define __Pyx_PyMethod_New(func, self, klass) ((self) ? PyMethod_New(func, self) : (Py_INCREF(func), func))
-#else
-  #define __Pyx_PyMethod_New(func, self, klass) PyMethod_New(func, self, klass)
-#endif
-
 // backport of PyAsyncMethods from Py3.5 to older Py3.x versions
 // (mis-)using the "tp_reserved" type slot which is re-activated as "tp_as_async" in Py3.5
 #if CYTHON_USE_ASYNC_SLOTS

Cython/Utility/ObjectHandling.c

@@ -2446,3 +2446,20 @@ static CYTHON_INLINE int __Pyx_object_dict_version_matches(PyObject* obj, PY_UIN
     return obj_dict_version == __Pyx_get_object_dict_version(obj);
 }
 #endif
+
+
+/////////////// PyMethodNew.proto ///////////////
+
+#if PY_MAJOR_VERSION >= 3
+// This should be an actual function (not a macro), such that we can put it
+// directly in a tp_descr_get slot.
+static PyObject *__Pyx_PyMethod_New(PyObject *func, PyObject *self, CYTHON_UNUSED PyObject *typ) {
+    if (!self) {
+        Py_INCREF(func);
+        return func;
+    }
+    return PyMethod_New(func, self);
+}
+#else
+    #define __Pyx_PyMethod_New PyMethod_New
+#endif