delete dead code
diff --git a/Python/ast.c b/Python/ast.c
index deea579..76daf6f 100644
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -3149,9 +3149,6 @@
                          "unexpected flow_stmt: %d", TYPE(ch));
             return NULL;
     }
-
-    PyErr_SetString(PyExc_SystemError, "unhandled flow statement");
-    return NULL;
 }
 
 static alias_ty