Follow another fast-call signature change in CPython 3.7.

https://bugs.python.org/issue32240

Cython/Utility/ModuleSetupCode.c

@@ -383,14 +383,18 @@ class __Pyx_FakeReference {
   #define Py_TPFLAGS_HAVE_FINALIZE 0
 #endif
 
-#if PY_VERSION_HEX < 0x030700A0 || !defined(METH_FASTCALL)
-  // new in CPython 3.6, but changed in 3.7 - see https://bugs.python.org/issue29464
+#if PY_VERSION_HEX <= 0x030700A3 || !defined(METH_FASTCALL)
+  // new in CPython 3.6, but changed in 3.7 - see
+  // positional-only parameters:
+  //   https://bugs.python.org/issue29464
+  // const args:
+  //   https://bugs.python.org/issue32240
   #ifndef METH_FASTCALL
      #define METH_FASTCALL 0x80
   #endif
-  typedef PyObject *(*__Pyx_PyCFunctionFast) (PyObject *self, PyObject **args, Py_ssize_t nargs);
+  typedef PyObject *(*__Pyx_PyCFunctionFast) (PyObject *self, PyObject *const *args, Py_ssize_t nargs);
   // new in CPython 3.7, used to be old signature of _PyCFunctionFast() in 3.6
-  typedef PyObject *(*__Pyx_PyCFunctionFastWithKeywords) (PyObject *self, PyObject **args,
+  typedef PyObject *(*__Pyx_PyCFunctionFastWithKeywords) (PyObject *self, PyObject *const *args,
                                                           Py_ssize_t nargs, PyObject *kwnames);
 #else
   #define __Pyx_PyCFunctionFast _PyCFunctionFast