Function eager_expand

fn eager_expand<'ob>(
    obj: &Rt<Slot<Gc<ObjectType<'_>>>>,
    macroexpand: &Rt<Slot<Gc<FunctionType<'_>>>>,
    env: &mut Rt<Env<'_>>,
    cx: &'ob mut Context<'_>,
) -> Result<Gc<ObjectType<'ob>>, Error>