bpo-33029: Fix signatures of getter and setter functions. (GH-10746)


Fix also return type for few other functions (clear, releasebuffer).
(cherry picked from commit d4f9cf5545d6d8844e0726552ef2e366f5cc3abd)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
diff --git a/Objects/cellobject.c b/Objects/cellobject.c
index 7b05e61..6f8915a 100644
--- a/Objects/cellobject.c
+++ b/Objects/cellobject.c
@@ -111,7 +111,7 @@
 }
 
 static int
-cell_set_contents(PyCellObject *op, PyObject *obj)
+cell_set_contents(PyCellObject *op, PyObject *obj, void *Py_UNUSED(ignored))
 {
     Py_XINCREF(obj);
     Py_XSETREF(op->ob_ref, obj);