Fix unused import warnings.

Signed-off-by: OGINO Masanori <masanori.ogino@gmail.com>

Author: omasanori

src/librustc/driver/driver.rs

@@ -1181,7 +1181,6 @@ mod test {
     use getopts::getopts;
     use syntax::attr;
     use syntax::attr::AttrMetaMethods;
-    use syntax::diagnostic;
 
     // When the user supplies --test we should implicitly supply --cfg test
     #[test]

src/libstd/unit.rs

@@ -12,6 +12,7 @@
 
 #[cfg(not(test))]
 use default::Default;
+#[cfg(not(test))]
 use cmp::{Eq, Equal, Ord, Ordering, TotalEq, TotalOrd};
 
 #[cfg(not(test))]

src/libsyntax/ext/expand.rs

@@ -890,17 +890,15 @@ fn original_span(cx: &ExtCtxt) -> @codemap::ExpnInfo {
 mod test {
     use super::*;
     use ast;
-    use ast::{Attribute_, AttrOuter, MetaWord, EMPTY_CTXT};
-    use ast_util::{get_sctable, mtwt_marksof, mtwt_resolve, new_rename};
+    use ast::{Attribute_, AttrOuter, MetaWord};
+    use ast_util::{get_sctable, mtwt_marksof, mtwt_resolve};
     use ast_util;
     use codemap;
     use codemap::Spanned;
-    use fold::*;
     use ext::base::{CrateLoader, MacroCrate};
     use parse;
-    use parse::token::{fresh_mark, gensym, intern};
     use parse::token;
-    use util::parser_testing::{string_to_crate, string_to_crate_and_sess};
+    use util::parser_testing::{string_to_crate_and_sess};
     use util::parser_testing::{string_to_pat, strs_to_idents};
     use visit;
     use visit::Visitor;