remove unused imports

src/librustdoc/desc_to_brief_pass.rs

@@ -24,7 +24,6 @@ use fold::Fold;
 use fold;
 use pass::Pass;
 
-use core::str;
 use core::util;
 
 pub fn mk_pass() -> Pass {

src/librustdoc/markdown_pass.rs

@@ -22,7 +22,6 @@ use markdown_writer::WriterFactory;
 use pass::Pass;
 use sort_pass;
 
-use core::iterator::IteratorUtil;
 use core::cell::Cell;
 use core::str;
 use core::vec;

src/librustdoc/text_pass.rs

@@ -149,8 +149,6 @@ mod test {
     use sectionalize_pass;
     use text_pass::mk_pass;
 
-    use core::str;
-
     fn mk_doc(source: ~str) -> doc::Doc {
         do astsrv::from_str(copy source) |srv| {
             let doc = extract::from_srv(srv.clone(), ~"");