message: Apply cargo clippy --fix
  Summary: as in title
diff: @@ -93,14 +93,14 @@ mod liveness {
  self.pred_edges
  .get(&n)
  .map(|v| v.iter().copied().collect())
  - .unwrap_or_else(|| SmallVec::new())
  + .unwrap_or_else(SmallVec::new)
  }
  fn successors(&self, n: Self::NodeId) -> SmallVec<[Self::EdgeId; DEFAULT_GRAPH_SUCCS_NUM]> {
  self.edges
  .get(&n)
  .map(|v| v.iter().copied().collect())
  - .unwrap_or_else(|| SmallVec::new())
  + .unwrap_or_else(SmallVec::new)
  }
  fn source(&self, e: Self::EdgeId) -> Self::NodeId {
  