rustc: Don't copy in add_used_link_args

Author: z0w0

src/librustc/metadata/creader.rs

@@ -196,7 +196,7 @@ fn visit_item(e: @mut Env, i: @ast::item) {
         for link_args.each |a| {
             match attr::get_meta_item_value_str(attr::attr_meta(*a)) {
               Some(ref linkarg) => {
-                cstore::add_used_link_args(cstore, (/*bad*/copy *linkarg));
+                cstore::add_used_link_args(cstore, *linkarg);
               }
               None => {/* fallthrough */ }
             }

src/librustc/metadata/cstore.rs

@@ -119,7 +119,7 @@ pub fn get_used_libraries(cstore: @mut CStore) -> ~[~str] {
     return /*bad*/copy cstore.used_libraries;
 }
 
-pub fn add_used_link_args(cstore: @mut CStore, args: ~str) {
+pub fn add_used_link_args(cstore: @mut CStore, args: &str) {
     cstore.used_link_args.push_all(str::split_char(args, ' '));
 }