Refactor ty::FnSig to privatize all fields

Author: Mark-Simulacrum

src/librustc/middle/intrinsicck.rs

@@ -178,8 +178,8 @@ impl<'a, 'gcx, 'tcx> Visitor<'gcx> for ExprVisitor<'a, 'gcx, 'tcx> {
                 let typ = self.infcx.tcx.tables().node_id_to_type(expr.id);
                 match typ.sty {
                     ty::TyFnDef(.., ref bare_fn_ty) if bare_fn_ty.abi == RustIntrinsic => {
-                        let from = bare_fn_ty.sig.0.inputs[0];
-                        let to = bare_fn_ty.sig.0.output;
+                        let from = bare_fn_ty.sig.skip_binder().inputs()[0];
+                        let to = bare_fn_ty.sig.skip_binder().output();
                         self.check_transmute(expr.span, from, to, expr.id);
                     }
                     _ => {

src/librustc/traits/object_safety.rs

@@ -241,12 +241,12 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
         // The `Self` type is erased, so it should not appear in list of
         // arguments or return type apart from the receiver.
         let ref sig = self.item_type(method.def_id).fn_sig();
-        for &input_ty in &sig.0.inputs[1..] {
+        for input_ty in &sig.skip_binder().inputs()[1..] {
             if self.contains_illegal_self_type_reference(trait_def_id, input_ty) {
                 return Some(MethodViolationCode::ReferencesSelf);
             }
         }
-        if self.contains_illegal_self_type_reference(trait_def_id, sig.0.output) {
+        if self.contains_illegal_self_type_reference(trait_def_id, sig.output().skip_binder()) {
             return Some(MethodViolationCode::ReferencesSelf);
         }