trans: Change @ast::Pat and @mut CrateContext in a few places

Use borrowed references in a few locations that were encountered when
working on other changes.

src/librustc/middle/check_match.rs

@@ -121,7 +121,7 @@ pub fn check_arms(cx: &MatchCheckCtxt, arms: &[Arm]) {
         for pat in arm.pats.iter() {
 
             // Check that we do not match against a static NaN (#6804)
-            let pat_matches_nan: &fn(@Pat) -> bool = |p| {
+            let pat_matches_nan: &fn(&Pat) -> bool = |p| {
                 match cx.tcx.def_map.find(&p.id) {
                     Some(&DefStatic(did, false)) => {
                         let const_expr = lookup_const_by_id(cx.tcx, did).unwrap();
@@ -893,7 +893,7 @@ pub fn check_legality_of_move_bindings(cx: &MatchCheckCtxt,
         }
     }
 
-    let check_move: &fn(@Pat, Option<@Pat>) = |p, sub| {
+    let check_move: &fn(&Pat, Option<@Pat>) = |p, sub| {
         // check legality of moving out of the enum
 
         // x @ Foo(*) is legal, but x @ Foo(y) isn't.

src/librustc/middle/resolve.rs

@@ -5410,7 +5410,7 @@ impl Resolver {
     }
 
     pub fn enforce_default_binding_mode(&mut self,
-                                        pat: @Pat,
+                                        pat: &Pat,
                                         pat_binding_mode: BindingMode,
                                         descr: &str) {
         match pat_binding_mode {

src/librustc/middle/trans/base.rs

@@ -2485,7 +2485,7 @@ pub fn item_path(ccx: &CrateContext, id: &ast::NodeId) -> path {
     ty::item_path(ccx.tcx, ast_util::local_def(*id))
 }
 
-fn exported_name(ccx: @mut CrateContext, path: path, ty: ty::t, attrs: &[ast::Attribute]) -> ~str {
+fn exported_name(ccx: &mut CrateContext, path: path, ty: ty::t, attrs: &[ast::Attribute]) -> ~str {
     match attr::first_attr_value_str_by_name(attrs, "export_name") {
         // Use provided name
         Some(name) => name.to_owned(),
@@ -2979,7 +2979,7 @@ pub fn decl_crate_map(sess: session::Session, mapmeta: LinkMeta,
     return map;
 }
 
-pub fn fill_crate_map(ccx: @mut CrateContext, map: ValueRef) {
+pub fn fill_crate_map(ccx: &mut CrateContext, map: ValueRef) {
     let mut subcrates: ~[ValueRef] = ~[];
     let mut i = 1;
     let cstore = ccx.sess.cstore;
@@ -3030,7 +3030,7 @@ pub fn crate_ctxt_to_encode_parms<'r>(cx: &'r CrateContext, ie: encoder::encode_
         }
 }
 
-pub fn write_metadata(cx: &mut CrateContext, crate: &ast::Crate) {
+pub fn write_metadata(cx: &CrateContext, crate: &ast::Crate) {
     if !*cx.sess.building_library { return; }
 
     let encode_inlined_item: encoder::encode_inlined_item =