From 358cd30287cc6e2b901bea874dc77821f17477d8 Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Mon, 3 Jul 2023 22:35:28 +0000
Subject: [PATCH] Coercion doesn't need binders either

---
 compiler/rustc_hir_typeck/src/coercion.rs | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/compiler/rustc_hir_typeck/src/coercion.rs b/compiler/rustc_hir_typeck/src/coercion.rs
index 29c0646a86e..108e20ed145 100644
--- a/compiler/rustc_hir_typeck/src/coercion.rs
+++ b/compiler/rustc_hir_typeck/src/coercion.rs
@@ -632,9 +632,8 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> {
         while !queue.is_empty() {
             let obligation = queue.remove(0);
             debug!("coerce_unsized resolve step: {:?}", obligation);
-            let bound_predicate = obligation.predicate.kind();
-            let trait_pred = match bound_predicate.skip_binder() {
-                ty::PredicateKind::Clause(ty::ClauseKind::Trait(trait_pred))
+            let trait_pred = match obligation.predicate.kind().no_bound_vars() {
+                Some(ty::PredicateKind::Clause(ty::ClauseKind::Trait(trait_pred)))
                     if traits.contains(&trait_pred.def_id()) =>
                 {
                     if unsize_did == trait_pred.def_id() {
@@ -652,20 +651,20 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> {
                             has_unsized_tuple_coercion = true;
                         }
                     }
-                    bound_predicate.rebind(trait_pred)
+                    trait_pred
                 }
                 _ => {
                     coercion.obligations.push(obligation);
                     continue;
                 }
             };
-            match selcx.poly_select(&obligation.with(selcx.tcx(), trait_pred)) {
+            match selcx.select(&obligation.with(selcx.tcx(), trait_pred)) {
                 // Uncertain or unimplemented.
                 Ok(None) => {
                     if trait_pred.def_id() == unsize_did {
                         let trait_pred = self.resolve_vars_if_possible(trait_pred);
-                        let self_ty = trait_pred.skip_binder().self_ty();
-                        let unsize_ty = trait_pred.skip_binder().trait_ref.substs[1].expect_ty();
+                        let self_ty = trait_pred.self_ty();
+                        let unsize_ty = trait_pred.trait_ref.substs[1].expect_ty();
                         debug!("coerce_unsized: ambiguous unsize case for {:?}", trait_pred);
                         match (self_ty.kind(), unsize_ty.kind()) {
                             (&ty::Infer(ty::TyVar(v)), ty::Dynamic(..))