message: Normalize main return type during mono item collection & codegen
diff: @@ -51,7 +51,10 @@ fn create_entry_fn(
  // late-bound regions, since late-bound
  // regions must appear in the argument
  // listing.
  - let main_ret_ty = tcx.erase_regions(main_ret_ty.no_bound_vars().unwrap());
  + let main_ret_ty = tcx.normalize_erasing_regions(
  + ty::ParamEnv::reveal_all(),
  + main_ret_ty.no_bound_vars().unwrap(),
  + );
  let cmain_sig = Signature {
  params: vec![
  