Remove unused imports

src/liballoc/arc.rs

@@ -600,11 +600,9 @@ mod tests {
     use std::ops::Drop;
     use std::option::Option;
     use std::option::Option::{Some, None};
-    use std::str::Str;
     use std::sync::atomic;
     use std::sync::atomic::Ordering::{Acquire, SeqCst};
     use std::task;
-    use std::kinds::Send;
     use std::vec::Vec;
     use super::{Arc, Weak, weak_count, strong_count};
     use std::sync::Mutex;

src/libcollections/bit.rs

@@ -1876,14 +1876,9 @@ impl<'a> Iterator<uint> for SymmetricDifference<'a> {
 #[cfg(test)]
 mod tests {
     use prelude::*;
-    use core::iter::range_step;
     use core::u32;
-    use std::rand;
-    use std::rand::Rng;
-    use test::{Bencher, black_box};
 
-    use super::{Bitv, BitvSet, from_fn, from_bytes};
-    use bitv;
+    use super::{Bitv, from_fn, from_bytes};
 
     #[test]
     fn test_to_str() {

src/libcollections/ring_buf.rs

@@ -1418,7 +1418,6 @@ mod tests {
     use self::Taggy::*;
     use self::Taggypar::*;
     use prelude::*;
-    use core::cmp;
     use core::iter;
     use std::fmt::Show;
     use std::hash;

src/libcoretest/char.rs

@@ -10,7 +10,7 @@
 //
 // ignore-lexer-test FIXME #15679
 
-use core::char::{escape_unicode, escape_default};
+use core::char::escape_default;
 
 #[test]
 fn test_is_lowercase() {

src/libcoretest/num/mod.rs

@@ -13,7 +13,6 @@ use core::fmt::Show;
 use core::num::{NumCast, cast};
 use core::ops::{Add, Sub, Mul, Div, Rem};
 use core::kinds::Copy;
-use std::str::from_str;
 
 mod int_macros;
 mod i8;

src/libgraphviz/lib.rs

@@ -589,7 +589,6 @@ mod tests {
     use super::{Id, LabelText, LabelStr, EscStr, Labeller};
     use super::{Nodes, Edges, GraphWalk, render};
     use std::io::IoResult;
-    use std::str;
     use std::borrow::IntoCow;
 
     /// each node is an index in a vector in the graph.

src/librustc_back/rpath.rs

@@ -151,7 +151,6 @@ fn minimize_rpaths(rpaths: &[String]) -> Vec<String> {
 mod test {
     use super::{RPathConfig};
     use super::{minimize_rpaths, rpaths_to_flags, get_rpath_relative_to_output};
-    use syntax::abi;
 
     #[test]
     fn test_rpaths_to_flags() {

src/libsyntax/ast.rs

@@ -1667,7 +1667,6 @@ mod test {
     // are ASTs encodable?
     #[test]
     fn check_asts_encodable() {
-        use std::io;
         let e = Crate {
             module: Mod {
                 inner: Span {