Issue #23571: _Py_CheckFunctionResult() now gives the name of the function

which returned an invalid result (result+error or no result without error) in
the exception message.

Add also unit test to check that the exception contains the name of the
function.

Special case: the final _PyEval_EvalFrameEx() check doesn't mention the
function since it didn't execute a single function but a whole frame.

Objects/methodobject.c

@@ -142,7 +142,7 @@ PyCFunction_Call(PyObject *func, PyObject *args, PyObject *kwds)
         }
     }
 
-    return _Py_CheckFunctionResult(res, "PyCFunction_Call");
+    return _Py_CheckFunctionResult(func, res, NULL);
 }
 
 /* Methods (the standard built-in methods, that is) */