remove old types from rustc_middle

Author: ZuseZ4

compiler/rustc_middle/src/middle/autodiff_attrs.rs

@@ -32,7 +32,6 @@ pub mod privacy;
 pub mod region;
 pub mod resolve_bound_vars;
 pub mod stability;
-pub mod typetree;
 
 pub fn provide(providers: &mut crate::query::Providers) {
     limits::provide(providers);