Use DefineOpaqueTypes::Yes since we are guaranteed to error already

Author: oli-obk

compiler/rustc_hir_typeck/src/demand.rs

@@ -400,7 +400,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     // what our ideal rcvr ty would look like.
                     let _ = self
                         .at(&ObligationCause::dummy(), self.param_env)
-                        .eq(DefineOpaqueTypes::No, method.sig.inputs()[idx + 1], arg_ty)
+                        .eq(DefineOpaqueTypes::Yes, method.sig.inputs()[idx + 1], arg_ty)
                         .ok()?;
                     self.select_obligations_where_possible(|errs| {
                         // Yeet the errors, we're already reporting errors.
@@ -479,7 +479,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     .and_then(|method| {
                         let _ = self
                             .at(&ObligationCause::dummy(), self.param_env)
-                            .eq(DefineOpaqueTypes::No, ideal_rcvr_ty, expected_ty)
+                            .eq(DefineOpaqueTypes::Yes, ideal_rcvr_ty, expected_ty)
                             .ok()?;
                         Some(method)
                     });

compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs

@@ -687,7 +687,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // Using probe here, since we don't want this subtyping to affect inference.
             let subtyping_error = self.probe(|_| {
                 self.at(&self.misc(arg_span), self.param_env)
-                    .sup(DefineOpaqueTypes::No, formal_input_ty, coerced_ty)
+                    .sup(DefineOpaqueTypes::Yes, formal_input_ty, coerced_ty)
                     .err()
             });