get rid of to_poly_trait_predicate

compiler/rustc_middle/src/ty/mod.rs

@@ -1153,6 +1153,25 @@ impl<'tcx> ToPredicate<'tcx, Predicate<'tcx>> for Binder<'tcx, PredicateKind<'tc
     }
 }
 
+impl<'tcx> ToPredicate<'tcx, Predicate<'tcx>> for Binder<'tcx, TraitRef<'tcx>> {
+    #[inline(always)]
+    fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> {
+        let pred: PolyTraitPredicate<'tcx> = self.to_predicate(tcx);
+        pred.to_predicate(tcx)
+    }
+}
+
+impl<'tcx> ToPredicate<'tcx, PolyTraitPredicate<'tcx>> for Binder<'tcx, TraitRef<'tcx>> {
+    #[inline(always)]
+    fn to_predicate(self, _: TyCtxt<'tcx>) -> PolyTraitPredicate<'tcx> {
+        self.map_bound(|trait_ref| TraitPredicate {
+            trait_ref,
+            constness: ty::BoundConstness::NotConst,
+            polarity: ty::ImplPolarity::Positive,
+        })
+    }
+}
+
 impl<'tcx> ToPredicate<'tcx, Predicate<'tcx>> for PolyTraitPredicate<'tcx> {
     fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> {
         self.map_bound(PredicateKind::Trait).to_predicate(tcx)

compiler/rustc_middle/src/ty/sty.rs

@@ -853,23 +853,6 @@ impl<'tcx> PolyTraitRef<'tcx> {
     pub fn def_id(&self) -> DefId {
         self.skip_binder().def_id
     }
-
-    pub fn to_poly_trait_predicate(&self) -> ty::PolyTraitPredicate<'tcx> {
-        self.map_bound(|trait_ref| ty::TraitPredicate {
-            trait_ref,
-            constness: ty::BoundConstness::NotConst,
-            polarity: ty::ImplPolarity::Positive,
-        })
-    }
-
-    /// Same as [`PolyTraitRef::to_poly_trait_predicate`] but sets a negative polarity instead.
-    pub fn to_poly_trait_predicate_negative_polarity(&self) -> ty::PolyTraitPredicate<'tcx> {
-        self.map_bound(|trait_ref| ty::TraitPredicate {
-            trait_ref,
-            constness: ty::BoundConstness::NotConst,
-            polarity: ty::ImplPolarity::Negative,
-        })
-    }
 }
 
 impl rustc_errors::IntoDiagnosticArg for PolyTraitRef<'_> {