make mk_closure take a ClosureSubsts

src/librustc/infer/freshen.rs

@@ -256,7 +256,7 @@ impl<'a, 'gcx, 'tcx> TypeFolder<'gcx, 'tcx> for TypeFreshener<'a, 'gcx, 'tcx> {
                         let closure_sig = this.infcx.fn_sig(def_id);
                         (tcx.mk_fn_ptr(closure_sig.fold_with(this)), tcx.types.char)
                     },
-                    |substs| tcx.mk_closure(def_id, substs)
+                    |substs| tcx.mk_closure(def_id, ty::ClosureSubsts { substs })
                 )
             }
 

src/librustc/ty/context.rs

@@ -1981,11 +1981,9 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
 
     pub fn mk_closure(self,
                       closure_id: DefId,
-                      substs: &'tcx Substs<'tcx>)
+                      substs: ClosureSubsts<'tcx>)
                       -> Ty<'tcx> {
-        self.mk_closure_from_closure_substs(closure_id, ClosureSubsts {
-            substs,
-        })
+        self.mk_closure_from_closure_substs(closure_id, substs)
     }
 
     pub fn mk_closure_from_closure_substs(self,

src/librustc_typeck/check/closure.rs

@@ -103,11 +103,11 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                     .next_ty_var(TypeVariableOrigin::ClosureSynthetic(expr.span))
             },
         );
+        let substs = ty::ClosureSubsts { substs };
         let closure_type = self.tcx.mk_closure(expr_def_id, substs);
 
         if let Some(interior) = interior {
-            let closure_substs = ty::ClosureSubsts { substs: substs };
-            return self.tcx.mk_generator(expr_def_id, closure_substs, interior);
+            return self.tcx.mk_generator(expr_def_id, substs, interior);
         }
 
         debug!(

src/librustc_typeck/collect.rs

@@ -1163,14 +1163,19 @@ fn type_of<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
                 return tcx.typeck_tables_of(def_id).node_id_to_type(hir_id);
             }
 
-            tcx.mk_closure(def_id, Substs::for_item(
-                tcx, def_id,
+            let substs = ty::ClosureSubsts {
+                substs: Substs::for_item(
+                    tcx,
+                    def_id,
                     |def, _| {
                         let region = def.to_early_bound_region_data();
                         tcx.mk_region(ty::ReEarlyBound(region))
                     },
                     |def, _| tcx.mk_param_from_def(def)
-            ))
+                )
+            };
+
+            tcx.mk_closure(def_id, substs)
         }
 
         NodeExpr(_) => match tcx.hir.get(tcx.hir.get_parent_node(node_id)) {