message: stop using Instance::def_ty
  that function has been removed
diff: @@ -105,7 +105,7 @@ pub fn eval_main<'a, 'tcx: 'a>(
  // First argument: pointer to main()
  let main_ptr = ecx.memory_mut().create_fn_alloc(main_instance);
  let dest = ecx.eval_place(&mir::Place::Local(args.next().unwrap()))?;
  - let main_ty = main_instance.def.def_ty(ecx.tcx);
  + let main_ty = main_instance.ty(ecx.tcx);
  let main_ptr_ty = ecx.tcx.mk_fn_ptr(main_ty.fn_sig(ecx.tcx));
  ecx.write_value(
  ValTy {
  