Function call_closure

pub(crate) fn call_closure<'ob>(
    closure: &Rt<Slot<Gc<&Cons>>>,
    arg_cnt: usize,
    name: &str,
    env: &mut Rt<Env<'_>>,
    cx: &'ob mut Context<'_>,
) -> Result<Gc<ObjectType<'ob>>, EvalError>