small mir typeck cleanup

Author: lcnr

compiler/rustc_borrowck/src/type_check/canonical.rs

@@ -90,12 +90,13 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
         locations: Locations,
         category: ConstraintCategory<'tcx>,
     ) {
-        self.prove_predicates(
-            Some(ty::Binder::dummy(ty::PredicateKind::Trait(ty::TraitPredicate {
+        self.prove_predicate(
+            ty::Binder::dummy(ty::PredicateKind::Trait(ty::TraitPredicate {
                 trait_ref,
                 constness: ty::BoundConstness::NotConst,
                 polarity: ty::ImplPolarity::Positive,
-            }))),
+            }))
+            .to_predicate(self.tcx()),
             locations,
             category,
         );

compiler/rustc_borrowck/src/type_check/free_region_relations.rs

@@ -268,7 +268,7 @@ impl<'tcx> UniversalRegionRelationsBuilder<'_, 'tcx> {
                 // }
                 // impl Foo for () {
                 //   type Bar = ();
-                //   fn foo(&self) ->&() {}
+                //   fn foo(&self) -> &() {}
                 // }
                 // ```
                 // Both &Self::Bar and &() are WF

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -1911,7 +1911,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                 }
             }
 
-            &Rvalue::NullaryOp(_, ty) => {
+            &Rvalue::NullaryOp(NullOp::SizeOf | NullOp::AlignOf, ty) => {
                 let trait_ref = ty::TraitRef {
                     def_id: tcx.require_lang_item(LangItem::Sized, Some(self.last_span)),
                     substs: tcx.mk_substs_trait(ty, &[]),