nit: use graph::{self, ..}

Author: nikomatsakis

src/librustc/mir/mod.rs

@@ -22,8 +22,7 @@ use mir::visit::MirVisitable;
 use rustc_apfloat::ieee::{Double, Single};
 use rustc_apfloat::Float;
 use rustc_data_structures::graph::dominators::{dominators, Dominators};
-use rustc_data_structures::graph;
-use rustc_data_structures::graph::{GraphPredecessors, GraphSuccessors};
+use rustc_data_structures::graph::{self, GraphPredecessors, GraphSuccessors};
 use rustc_data_structures::indexed_vec::{Idx, IndexVec};
 use rustc_data_structures::small_vec::SmallVec;
 use rustc_data_structures::sync::Lrc;