rustc: use intern_* instead of mk_* where possible.

src/librustc/ty/context.rs

@@ -2600,7 +2600,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
     }
 
     pub fn mk_goal(self, goal: Goal<'tcx>) -> &'tcx Goal {
-        &self.mk_goals(iter::once(goal))[0]
+        &self.intern_goals(&[goal])[0]
     }
 
     pub fn lint_node<S: Into<MultiSpan>>(self,

src/librustc_codegen_llvm/common.rs

@@ -431,8 +431,10 @@ pub fn ty_fn_sig<'a, 'tcx>(cx: &CodegenCx<'a, 'tcx>,
             sig.map_bound(|sig| {
                 let state_did = tcx.lang_items().gen_state().unwrap();
                 let state_adt_ref = tcx.adt_def(state_did);
-                let state_substs = tcx.mk_substs([sig.yield_ty.into(),
+                let state_substs = tcx.intern_substs(&[
-                    sig.return_ty.into()].iter());
+                    sig.yield_ty.into(),
+                    sig.return_ty.into(),
+                ]);
                 let ret_ty = tcx.mk_adt(state_adt_ref, state_substs);
 
                 tcx.mk_fn_sig(iter::once(env_ty),

src/librustc_mir/borrow_check/nll/universal_regions.rs

@@ -669,7 +669,7 @@ impl<'cx, 'gcx, 'tcx> UniversalRegionsBuilder<'cx, 'gcx, 'tcx> {
                 assert_eq!(self.mir_def_id, def_id);
                 let ty = tcx.type_of(def_id);
                 let ty = indices.fold_to_region_vids(tcx, &ty);
-                ty::Binder::dummy(tcx.mk_type_list(iter::once(ty)))
+                ty::Binder::dummy(tcx.intern_type_list(&[ty]))
             }
         }
     }

src/librustc_mir/shim.rs

@@ -170,7 +170,7 @@ fn build_drop_shim<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
     }
 
     let substs = if let Some(ty) = ty {
-        tcx.mk_substs(iter::once(ty.into()))
+        tcx.intern_substs(&[ty.into()])
     } else {
         Substs::identity_for_item(tcx, def_id)
     };

src/librustc_mir/transform/generator.rs

@@ -861,8 +861,10 @@ impl MirPass for StateTransform {
         // Compute GeneratorState<yield_ty, return_ty>
         let state_did = tcx.lang_items().gen_state().unwrap();
         let state_adt_ref = tcx.adt_def(state_did);
-        let state_substs = tcx.mk_substs([yield_ty.into(),
+        let state_substs = tcx.intern_substs(&[
-            mir.return_ty().into()].iter());
+            yield_ty.into(),
+            mir.return_ty().into(),
+        ]);
         let ret_ty = tcx.mk_adt(state_adt_ref, state_substs);
 
         // We rename RETURN_PLACE which has type mir.return_ty to new_ret_local

src/librustc_traits/lowering.rs

@@ -220,7 +220,7 @@ fn program_clauses_for_trait<'a, 'tcx>(
     // `Implemented(Self: Trait<P1..Pn>) :- FromEnv(Self: Trait<P1..Pn>)`
     let implemented_from_env = ProgramClause {
         goal: impl_trait,
-        hypotheses: tcx.mk_goals(iter::once(from_env)),
+        hypotheses: tcx.intern_goals(&[from_env]),
     };
     let clauses = iter::once(Clause::ForAll(ty::Binder::dummy(implemented_from_env)));
 
@@ -256,7 +256,7 @@ fn implied_bound_from_trait<'a, 'tcx>(
     // `FromEnv(WC) :- FromEnv(Self: Trait<P1..Pn>)`
     Clause::ForAll(where_clause.lower().map_bound(|goal| ProgramClause {
         goal: goal.into_from_env_goal(),
-        hypotheses: tcx.mk_goals(iter::once(Goal::from(impl_trait))),
+        hypotheses: tcx.intern_goals(&[Goal::from(impl_trait)]),
     }))
 }
 
@@ -290,7 +290,7 @@ fn program_clauses_for_impl<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId
                 .map(|wc| Goal::from_poly_domain_goal(wc, tcx)),
         ),
     };
-    tcx.mk_clauses(iter::once(Clause::ForAll(ty::Binder::dummy(clause))))
+    tcx.intern_clauses(&[Clause::ForAll(ty::Binder::dummy(clause))])
 }
 
 pub fn program_clauses_for_associated_type_value<'a, 'tcx>(
@@ -344,7 +344,7 @@ pub fn program_clauses_for_associated_type_value<'a, 'tcx>(
                 .map(|wc| Goal::from_poly_domain_goal(wc, tcx)),
         ),
     };
-    tcx.mk_clauses(iter::once(Clause::ForAll(ty::Binder::dummy(clause))))
+    tcx.intern_clauses(&[Clause::ForAll(ty::Binder::dummy(clause))])
 }
 
 pub fn dump_program_clauses<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) {