Unify walk_qself

Author: maxcabrajac

compiler/rustc_ast/src/visitors.rs

@@ -552,6 +552,18 @@ macro_rules! make_ast_visitor {
             return_result!(V)
         }
 
+        pub fn walk_qself<$($lt,)? V: $trait$(<$lt>)?>(
+            vis: &mut V,
+            qself: ref_t!(Option<P<QSelf>>)
+        ) -> result!(V) {
+            if let Some(qself) = qself {
+                let QSelf { ty, path_span, position: _ } = &$($mut)? **qself;
+                try_v!(vis.visit_ty(ty));
+                try_v!(visit_span!(vis, path_span));
+            }
+            return_result!(V)
+        }
+
         pub fn walk_param<$($lt,)? V: $trait$(<$lt>)?>(
             vis: &mut V,
             param: ref_t!(Param)
@@ -999,14 +1011,6 @@ pub mod visit {
         V::Result::output()
     }
 
-    fn walk_qself<'a, V: Visitor<'a>>(visitor: &mut V, qself: &'a Option<P<QSelf>>) -> V::Result {
-        if let Some(qself) = qself {
-            let QSelf { ty, path_span: _, position: _ } = &**qself;
-            try_visit!(visitor.visit_ty(ty));
-        }
-        V::Result::output()
-    }
-
     pub fn walk_path<'a, V: Visitor<'a>>(visitor: &mut V, path: &'a Path) -> V::Result {
         let Path { span: _, segments, tokens: _ } = path;
         walk_list!(visitor, visit_path_segment, segments);
@@ -1817,14 +1821,6 @@ pub mod mut_visit {
         vis.visit_span(span);
     }
 
-    fn walk_qself<T: MutVisitor>(vis: &mut T, qself: &mut Option<P<QSelf>>) {
-        visit_opt(qself, |qself| {
-            let QSelf { ty, path_span, position: _ } = &mut **qself;
-            vis.visit_ty(ty);
-            vis.visit_span(path_span);
-        })
-    }
-
     fn walk_generic_arg<T: MutVisitor>(vis: &mut T, arg: &mut GenericArg) {
         match arg {
             GenericArg::Lifetime(lt) => vis.visit_lifetime(lt, LifetimeCtxt::GenericArg),