Use map_bound

Author: jackh726

Diff for: compiler/rustc_mir_transform/src/shim.rs

@@ -537,13 +537,12 @@ fn build_call_shim<'tcx>(
     };
 
     let def_id = instance.def_id();
-    let sig = tcx.fn_sig(def_id);
-    let mut sig = tcx.erase_late_bound_regions(sig);
+    let sig = tcx.bound_fn_sig(def_id);
+    let sig = sig.map_bound(|sig| tcx.erase_late_bound_regions(sig));
 
     assert_eq!(sig_substs.is_some(), !instance.has_polymorphic_mir_body());
-    if let Some(sig_substs) = sig_substs {
-        sig = EarlyBinder(sig).subst(tcx, sig_substs);
-    }
+    let mut sig =
+        if let Some(sig_substs) = sig_substs { sig.subst(tcx, sig_substs) } else { sig.0 };
 
     if let CallKind::Indirect(fnty) = call_kind {
         // `sig` determines our local decls, and thus the callee type in the `Call` terminator. This

Diff for: compiler/rustc_trait_selection/src/traits/select/confirmation.rs

@@ -12,7 +12,7 @@ use rustc_index::bit_set::GrowableBitSet;
 use rustc_infer::infer::InferOk;
 use rustc_infer::infer::LateBoundRegionConversionTime::HigherRankedType;
 use rustc_middle::ty::subst::{GenericArg, GenericArgKind, InternalSubsts, Subst, SubstsRef};
-use rustc_middle::ty::{self, EarlyBinder, GenericParamDefKind, Ty, TyCtxt};
+use rustc_middle::ty::{self, GenericParamDefKind, Ty, TyCtxt};
 use rustc_middle::ty::{ToPolyTraitRef, ToPredicate};
 use rustc_span::def_id::DefId;
 
@@ -555,7 +555,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
 
                         let bound_vars = tcx.mk_bound_variable_kinds(bound_vars.into_iter());
                         let bound =
-                            EarlyBinder(bound.0.kind().skip_binder()).subst(tcx, assoc_ty_substs);
+                            bound.map_bound(|b| b.kind().skip_binder()).subst(tcx, assoc_ty_substs);
                         tcx.mk_predicate(ty::Binder::bind_with_vars(bound, bound_vars))
                     };
                 let normalized_bound = normalize_with_depth_to(