Apply suggestions from code review

Co-authored-by: bjorn3 <[email protected]>

Author: osiewicz

compiler/rustc_codegen_ssa/src/back/symbol_export.rs

@@ -326,11 +326,11 @@ fn exported_symbols_provider_local(
         let is_local_to_current_crate = |ty: Ty<'_>| {
             let no_refs = ty.peel_refs();
             let root_def_id = match no_refs.kind() {
-                rustc_middle::ty::Closure(closure, _) => *closure,
-                rustc_middle::ty::FnDef(def_id, _) => *def_id,
-                rustc_middle::ty::Coroutine(def_id, _) => *def_id,
-                rustc_middle::ty::CoroutineClosure(def_id, _) => *def_id,
-                rustc_middle::ty::CoroutineWitness(def_id, _) => *def_id,
+                ty::Closure(closure, _) => *closure,
+                ty::FnDef(def_id, _) => *def_id,
+                ty::Coroutine(def_id, _) => *def_id,
+                ty::CoroutineClosure(def_id, _) => *def_id,
+                ty::CoroutineWitness(def_id, _) => *def_id,
                 _ => return false,
             };
             let Some(root_def_id) = root_def_id.as_local() else {
@@ -346,6 +346,7 @@ fn exported_symbols_provider_local(
                 arg.walk().all(|ty| ty.as_type().map_or(true, |ty| !is_local_to_current_crate(ty)))
             })
         };
+
         // The symbols created in this loop are sorted below it
         #[allow(rustc::potential_query_instability)]
         for (mono_item, data) in cgus.iter().flat_map(|cgu| cgu.items().iter()) {
@@ -395,13 +396,11 @@ fn exported_symbols_provider_local(
                     // A little sanity-check
                     assert_eq!(args.non_erasable_generics().next(), Some(GenericArgKind::Type(ty)));
 
-                    let root_identifier = match ty.kind() {
-                        rustc_middle::ty::Adt(def, args) => Some((def.did(), args)),
-                        rustc_middle::ty::Closure(id, args) => Some((*id, args)),
-                        _ => None,
+                    let should_export = match ty.kind() {
+                        ty::Adt(def, args) => is_instantiable_downstream(def.did(), args.types()),
+                        ty::Closure(id, args) => is_instantiable_downstream(*id, args.types()),
+                        _ => true,
                     };
-                    let should_export = root_identifier
-                        .map_or(true, |(did, args)| is_instantiable_downstream(did, args.types()));
 
                     if should_export {
                         symbols.push((