Link edges after adding a node too

Author: zetanumbers

compiler/rustc_data_structures/src/graph/linked_graph/mod.rs

@@ -129,6 +129,7 @@ impl<I: Idx, N, E> LinkedGraph<I, N, E> {
 
     pub fn add_node(&mut self, idx: I, data: N) {
         let old = self.nodes.insert(idx, Node::new(data));
+        self.link_edges();
         debug_assert!(old.is_none());
     }