bpo-35983: skip trashcan for subclasses (GH-11841)

Add new trashcan macros to deal with a double deallocation that could occur when the `tp_dealloc` of a subclass calls the `tp_dealloc` of a base class and that base class uses the trashcan mechanism.

Patch by Jeroen Demeyer.
diff --git a/Objects/setobject.c b/Objects/setobject.c
index a43ecd5..82e9639 100644
--- a/Objects/setobject.c
+++ b/Objects/setobject.c
@@ -559,7 +559,7 @@
 
     /* bpo-31095: UnTrack is needed before calling any callbacks */
     PyObject_GC_UnTrack(so);
-    Py_TRASHCAN_SAFE_BEGIN(so)
+    Py_TRASHCAN_BEGIN(so, set_dealloc)
     if (so->weakreflist != NULL)
         PyObject_ClearWeakRefs((PyObject *) so);
 
@@ -572,7 +572,7 @@
     if (so->table != so->smalltable)
         PyMem_DEL(so->table);
     Py_TYPE(so)->tp_free(so);
-    Py_TRASHCAN_SAFE_END(so)
+    Py_TRASHCAN_END
 }
 
 static PyObject *