Update to the latest stable rustfmt, 0.4.2-stable (febbb36 2018-04-12).

lib/codegen/src/ir/dfg.rs

@@ -1151,8 +1151,8 @@ mod tests {
 
     #[test]
     fn aliases() {
-        use ir::InstBuilder;
         use ir::condcodes::IntCC;
+        use ir::InstBuilder;
 
         let mut func = Function::new();
         let ebb0 = func.dfg.make_ebb();

lib/codegen/src/ir/heap.rs

@@ -1,7 +1,7 @@
 //! Heaps.
 
-use ir::GlobalVar;
 use ir::immediates::Imm64;
+use ir::GlobalVar;
 use std::fmt;
 
 /// Information about a heap declaration.

lib/codegen/src/ir/stackslot.rs

@@ -338,8 +338,8 @@ impl StackSlots {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use ir::Function;
     use ir::types;
+    use ir::Function;
     use std::string::ToString;
 
     #[test]