Reformat use declarations.

The previous commit updated `rustfmt.toml` appropriately. This commit is
the outcome of running `x fmt --all` with the new formatting options.

compiler/rustc_transmute/src/lib.rs

@@ -79,19 +79,15 @@ pub enum Reason<T> {
 
 #[cfg(feature = "rustc")]
 mod rustc {
-    use super::*;
-
     use rustc_hir::lang_items::LangItem;
     use rustc_infer::infer::InferCtxt;
     use rustc_macros::TypeVisitable;
     use rustc_middle::traits::ObligationCause;
-    use rustc_middle::ty::Const;
-    use rustc_middle::ty::ParamEnv;
-    use rustc_middle::ty::Ty;
-    use rustc_middle::ty::TyCtxt;
-    use rustc_middle::ty::ValTree;
+    use rustc_middle::ty::{Const, ParamEnv, Ty, TyCtxt, ValTree};
     use rustc_span::DUMMY_SP;
 
+    use super::*;
+
     /// The source and destination types of a transmutation.
     #[derive(TypeVisitable, Debug, Clone, Copy)]
     pub struct Types<'tcx> {