Unify walk_item

Author: maxcabrajac

compiler/rustc_ast/src/visitors.rs

@@ -1067,6 +1067,14 @@ macro_rules! make_ast_visitor {
             return_result!(V)
         }
 
+        pub fn walk_item<$($lt,)? V: $trait$(<$lt>)?, I: WalkItemKind>(
+            visitor: &mut V,
+            item: ref_t!(Item<I>)
+        ) -> result!(V) {
+            I::walk(item, visitor);
+            return_result!(V)
+        }
+
         derive_copy_clone!{
             #[derive(Debug)]
             pub enum FnKind<'a> {
@@ -1319,14 +1327,6 @@ pub mod visit {
         }
     }
 
-    pub fn walk_item<'a, V: Visitor<'a>, I: WalkItemKind>(
-        visitor: &mut V,
-        item: &'a Item<I>,
-    ) -> V::Result {
-        try_visit!(I::walk(item, visitor));
-        V::Result::output()
-    }
-
     pub fn walk_ty<'a, V: Visitor<'a>>(visitor: &mut V, typ: &'a Ty) -> V::Result {
         let Ty { id, kind, span: _, tokens: _ } = typ;
         match kind {
@@ -2427,9 +2427,6 @@ pub mod mut_visit {
         visit_safety(vis, safety);
     }
 
-    pub fn walk_item<K: WalkItemKind>(visitor: &mut impl MutVisitor, item: &mut Item<K>) {
-        K::walk(item, visitor);
-    }
     /// Mutates one item, returning the item again.
     pub fn walk_flat_map_item<K: WalkItemKind>(
         visitor: &mut impl MutVisitor,