Issue #28544: Fix compilation of _asynciomodule.c on Windows
diff --git a/Include/genobject.h b/Include/genobject.h
index 973bdd5..1ee4fd5 100644
--- a/Include/genobject.h
+++ b/Include/genobject.h
@@ -42,7 +42,7 @@
PyObject *name, PyObject *qualname);
PyAPI_FUNC(int) PyGen_NeedsFinalizing(PyGenObject *);
PyAPI_FUNC(int) _PyGen_FetchStopIterationValue(PyObject **);
-PyObject *_PyGen_Send(PyGenObject *, PyObject *);
+PyAPI_FUNC(PyObject *) _PyGen_Send(PyGenObject *, PyObject *);
PyObject *_PyGen_yf(PyGenObject *);
PyAPI_FUNC(void) _PyGen_Finalize(PyObject *self);