Use Inherited Visibility instead of None when no vis is present

compiler/rustc_parse/src/parser/ty.rs

@@ -474,8 +474,13 @@ impl<'a> Parser<'a> {
         params: Vec<GenericParam>,
         recover_return_sign: RecoverReturnSign,
     ) -> PResult<'a, TyKind> {
+        let inherited_vis = rustc_ast::Visibility {
+            span: rustc_span::DUMMY_SP,
+            kind: rustc_ast::VisibilityKind::Inherited,
+            tokens: None,
+        };
         let ast::FnHeader { ext, unsafety, constness, asyncness } =
-            self.parse_fn_front_matter(None)?;
+            self.parse_fn_front_matter(&inherited_vis)?;
         let decl = self.parse_fn_decl(|_| false, AllowPlus::No, recover_return_sign)?;
         let whole_span = lo.to(self.prev_token.span);
         if let ast::Const::Yes(span) = constness {