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_index/src/bit_set.rs

@@ -1,21 +1,16 @@
-use std::fmt;
-use std::iter;
 use std::marker::PhantomData;
-use std::mem;
 use std::ops::{BitAnd, BitAndAssign, BitOrAssign, Bound, Not, Range, RangeBounds, Shl};
 use std::rc::Rc;
-use std::slice;
+use std::{fmt, iter, mem, slice};
 
 use arrayvec::ArrayVec;
-use smallvec::{smallvec, SmallVec};
-
 #[cfg(feature = "nightly")]
 use rustc_macros::{Decodable_Generic, Encodable_Generic};
+use smallvec::{smallvec, SmallVec};
+use Chunk::*;
 
 use crate::{Idx, IndexVec};
 
-use Chunk::*;
-
 #[cfg(test)]
 mod tests;
 

compiler/rustc_index/src/bit_set/tests.rs

@@ -2,6 +2,7 @@ use super::*;
 
 extern crate test;
 use std::hint::black_box;
+
 use test::Bencher;
 
 #[test]

compiler/rustc_index/src/interval.rs

@@ -1,7 +1,6 @@
 use std::iter::Step;
 use std::marker::PhantomData;
-use std::ops::RangeBounds;
-use std::ops::{Bound, Range};
+use std::ops::{Bound, Range, RangeBounds};
 
 use smallvec::SmallVec;
 

compiler/rustc_index/src/lib.rs

@@ -12,9 +12,10 @@ mod idx;
 mod slice;
 mod vec;
 
-pub use {idx::Idx, slice::IndexSlice, vec::IndexVec};
-
+pub use idx::Idx;
 pub use rustc_index_macros::newtype_index;
+pub use slice::IndexSlice;
+pub use vec::IndexVec;
 
 /// Type size assertion. The first argument is a type and the second argument is its expected size.
 ///

compiler/rustc_index/src/slice.rs

@@ -1,9 +1,6 @@
-use std::{
-    fmt,
-    marker::PhantomData,
-    ops::{Index, IndexMut},
-    slice,
-};
+use std::marker::PhantomData;
+use std::ops::{Index, IndexMut};
+use std::{fmt, slice};
 
 use crate::{Idx, IndexVec};
 

compiler/rustc_index/src/vec.rs

@@ -1,13 +1,11 @@
-#[cfg(feature = "nightly")]
-use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
-
 use std::borrow::{Borrow, BorrowMut};
-use std::fmt;
 use std::hash::Hash;
 use std::marker::PhantomData;
 use std::ops::{Deref, DerefMut, RangeBounds};
-use std::slice;
-use std::vec;
+use std::{fmt, slice, vec};
+
+#[cfg(feature = "nightly")]
+use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
 
 use crate::{Idx, IndexSlice};