New trait solver is a property of inference context

compiler/rustc_hir_analysis/src/autoderef.rs

@@ -73,7 +73,7 @@ impl<'a, 'tcx> Iterator for Autoderef<'a, 'tcx> {
             // NOTE: we may still need to normalize the built-in deref in case
             // we have some type like `&<Ty as Trait>::Assoc`, since users of
             // autoderef expect this type to have been structurally normalized.
-            if self.infcx.tcx.trait_solver_next()
+            if self.infcx.next_trait_solver()
                 && let ty::Alias(ty::Projection, _) = ty.kind()
             {
                 let (normalized_ty, obligations) = self.structurally_normalize(ty)?;