message: CallEnter and CallExit of heap implement serde Serializable
diff: @@ -68,7 +68,7 @@ struct NoDrop;
  impl MaybeDrop for NeedsDrop {}
  impl MaybeDrop for NoDrop {}
  -#[derive(Trace, Debug, Display, AnyLifetime)]
  +#[derive(Trace, Debug, Display, AnyLifetime, NoSerialize)]
  #[display(fmt = "CallEnter")]
  struct CallEnter<'v, D: MaybeDrop + 'static> {
  function: Value<'v>,
  @@ -87,7 +87,7 @@ impl<'v, D: MaybeDrop + AnyLifetime<'v> + Trace<'v>> StarlarkValue<'v> for CallE
  starlark_type!("call_enter");
  }
  -#[derive(Debug, Display, AnyLifetime)]
  +#[derive(Debug, Display, AnyLifetime, NoSerialize)]
  #[display(fmt = "CallExit")]
  struct CallExit<D: MaybeDrop + 'static> {
  time: Instant,
  