rustc_trans: fix compilation

src/librustc_trans/collector.rs

@@ -1124,8 +1124,6 @@ impl<'b, 'a, 'v> ItemLikeVisitor<'v> for RootCollector<'b, 'a, 'v> {
             _ => { /* Nothing to do here */ }
         }
     }
-
-    fn visit_expr_id(&mut self, _: hir::ExprId) { }
 }
 
 fn create_trans_items_for_default_impls<'a, 'tcx>(scx: &SharedCrateContext<'a, 'tcx>,

src/librustc_trans/symbol_names_test.rs

@@ -81,7 +81,5 @@ impl<'a, 'tcx> Visitor<'tcx> for SymbolNamesTest<'a, 'tcx> {
         self.process_attrs(ii.id);
         intravisit::walk_impl_item(self, ii)
     }
-
-    fn visit_expr_id(&mut self, _: hir::ExprId) { }
 }