Issue #3299: replace PyObject_DEL() by Py_DECREF() in _sre module to fix a
crash in pydebug mode.
diff --git a/Modules/_sre.c b/Modules/_sre.c
index 7b3ee5f..8f3b8ce 100644
--- a/Modules/_sre.c
+++ b/Modules/_sre.c
@@ -2702,7 +2702,7 @@
 	else {
 		Py_ssize_t p_length;
 		if (!getstring(pattern, &p_length, &self->charsize)) {
-			PyObject_DEL(self);
+			Py_DECREF(self);
 			return NULL;
 		}
 	}