Rollup merge of #34446 - jseyfried:refactor_decorators, r=nrc

Treat `MultiDecorator`s as a special case of `MultiModifier`s

This deals with #32950 by using @durka's [option 1](https://github.com/rust-lang/rust/pull/33769#issuecomment-221774136).
r? @nrc

1 files changed, 6 insertions, 6 deletions

diff --git a/src/test/compile-fail/issue-32950.rs b/src/test/compile-fail/issue-32950.rs
index e47ebdd6a69..e8ca1c1fa98 100644
--- a/src/test/compile-fail/issue-32950.rs
+++ b/src/test/compile-fail/issue-32950.rs
@@ -8,11 +8,11 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(type_macros, concat_idents, rustc_attrs)]
-#![allow(unused)]
+#![feature(type_macros, concat_idents)]
 
-#[derive(Debug)] struct FooBar;
-#[derive(Debug)] struct Baz<T>(T, concat_idents!(Foo, Bar));
+#[derive(Debug)] //~ NOTE in this expansion
+struct Baz<T>(
+    concat_idents!(Foo, Bar) //~ ERROR `derive` cannot be used on items with type macros
+);
 
-#[rustc_error]
-fn main() {} //~ ERROR compilation successful
+fn main() {}