Avoid a call to PyTuple_GET_ITEM() to get the item array pointer if...

Avoid a call to PyTuple_GET_ITEM() to get the item array pointer if CYTHON_ASSUME_SAFE_MACROS is disabled.
See https://github.com/cython/cython/issues/3701

Cython/Utility/CythonFunction.c

@@ -652,7 +652,13 @@ static PyObject *__Pyx_CyFunction_CallAsMethod(PyObject *func, PyObject *args, P
     // CPython would normally use vectorcall directly instead of tp_call.
      __pyx_vectorcallfunc vc = __Pyx_CyFunction_func_vectorcall(cyfunc);
     if (vc) {
+#if CYTHON_ASSUME_SAFE_MACROS
         return __Pyx_PyVectorcall_FastCallDict(func, vc, &PyTuple_GET_ITEM(args, 0), PyTuple_GET_SIZE(args), kw);
+#else
+        // avoid unused function warning
+        (void) &__Pyx_PyVectorcall_FastCallDict;
+        return PyVectorcall_Call(func, args, kw);
+#endif
     }
 #endif