Fix test_gc() on limited C API 3.9 on Windows

PyObject_GC_IsTracked() and PyObject_GC_IsFinalized() are only added
to limited C API 3.10 on Windows.

Author: vstinner

docs/api.rst

@@ -809,13 +809,13 @@ GC protocol
 
    See `PyObject_GC_IsTracked() documentation <https://docs.python.org/dev/c-api/gcsupport.html#c.PyObject_GC_IsTracked>`__.
 
-   Not available on PyPy nor on limited C API 3.8 and older.
+   Not available on PyPy nor on limited C API 3.9 and older.
 
 .. c:function:: int PyObject_GC_IsFinalized(PyObject *obj)
 
    See `PyObject_GC_IsFinalized() documentation <https://docs.python.org/dev/c-api/gcsupport.html#c.PyObject_GC_IsFinalized>`__.
 
-   Availability: Python 3.4. Not available on PyPy nor on limited C API 3.8 and
+   Availability: Python 3.4. Not available on PyPy nor on limited C API 3.9 and
    older.
 
 Module helper

pythoncapi_compat.h

@@ -487,6 +487,7 @@ static inline int PyModule_AddType(PyObject *module, PyTypeObject *type)
 
 // bpo-40241 added PyObject_GC_IsTracked() to Python 3.9.0a6.
 // bpo-4688 added _PyObject_GC_IS_TRACKED() to Python 2.7.0a2.
+// On Windows, PyObject_GC_IsTracked() was only added to limited C API 3.10.
 #if PY_VERSION_HEX < 0x030900A6 && !defined(PYPY_VERSION) && !defined(Py_LIMITED_API)
 static inline int PyObject_GC_IsTracked(PyObject* obj)
 {
@@ -496,6 +497,7 @@ static inline int PyObject_GC_IsTracked(PyObject* obj)
 
 // bpo-40241 added PyObject_GC_IsFinalized() to Python 3.9.0a6.
 // bpo-18112 added _PyGCHead_FINALIZED() to Python 3.4.0 final.
+// On Windows, PyObject_GC_IsFinalized() was only added to limited C API 3.10.
 #if PY_VERSION_HEX < 0x030900A6 && !defined(PYPY_VERSION) && !defined(Py_LIMITED_API)
 static inline int PyObject_GC_IsFinalized(PyObject *obj)
 {

tests/test_pythoncapi_compat_cext.c

@@ -386,6 +386,7 @@ test_calls(PyObject *Py_UNUSED(module), PyObject* Py_UNUSED(ignored))
 }
 
 
+#if !(defined(Py_LIMITED_API) && PY_VERSION_HEX < 0x030A0000) && !defined(PYPY_VERSION)
 static PyObject *
 test_gc(PyObject *Py_UNUSED(module), PyObject* Py_UNUSED(ignored))
 {
@@ -394,21 +395,18 @@ test_gc(PyObject *Py_UNUSED(module), PyObject* Py_UNUSED(ignored))
         return NULL;
     }
 
-#if !(defined(Py_LIMITED_API) && PY_VERSION_HEX < 0x030900A6) && !defined(PYPY_VERSION)
     // test PyObject_GC_IsTracked()
     int tracked = PyObject_GC_IsTracked(tuple);
     assert(tracked);
-#endif
 
-#if !(defined(Py_LIMITED_API) && PY_VERSION_HEX < 0x030900A6) && !defined(PYPY_VERSION)
     // test PyObject_GC_IsFinalized()
     int finalized = PyObject_GC_IsFinalized(tuple);
     assert(!finalized);
-#endif
 
     Py_DECREF(tuple);
     Py_RETURN_NONE;
 }
+#endif
 
 
 static int
@@ -2547,7 +2545,9 @@ static struct PyMethodDef methods[] = {
 #endif
     {"test_interpreter", test_interpreter, METH_NOARGS, _Py_NULL},
     {"test_calls", test_calls, METH_NOARGS, _Py_NULL},
+#if !(defined(Py_LIMITED_API) && PY_VERSION_HEX < 0x030A0000) && !defined(PYPY_VERSION)
     {"test_gc", test_gc, METH_NOARGS, _Py_NULL},
+#endif
     {"test_module", test_module, METH_NOARGS, _Py_NULL},
 #if ((PY_VERSION_HEX <= 0x030B00A1 || 0x030B00A7 <= PY_VERSION_HEX) \
         && !defined(PYPY_VERSION) && !defined(Py_LIMITED_API))