message: Fixed types on `next` and `wait_next`
diff: @@ -477,12 +477,12 @@ pub fn standard(f: &mut Prelude) {
  });
  f.intrinsic(Arc::new("next".into()), NEXT, Dfn {
  lts: vec![Lt::Default],
  - tys: vec![Type::Any],
  + tys: vec![Type::in_ty()],
  ret: Type::Any
  });
  f.intrinsic(Arc::new("wait_next".into()), WAIT_NEXT, Dfn {
  lts: vec![Lt::Default],
  - tys: vec![Type::Any],
  + tys: vec![Type::in_ty()],
  ret: Type::Any
  });
  }
  