As suggested by Toby Dickenson, setting ob_type to NULL in
_Py_Dealloc(), is a bad idea (and always was!).  So let's drop it.
diff --git a/Objects/object.c b/Objects/object.c
index 3323906..4f395ff 100644
--- a/Objects/object.c
+++ b/Objects/object.c
@@ -978,10 +978,6 @@
 {
 	destructor dealloc = op->ob_type->tp_dealloc;
 	_Py_ForgetReference(op);
-#ifndef WITH_CYCLE_GC
-	if (_PyTrash_delete_nesting < PyTrash_UNWIND_LEVEL-1)
-		op->ob_type = NULL;
-#endif
 	(*dealloc)(op);
 }