Function require

pub(crate) fn require<'ob>(
    feature: &Rt<Slot<Gc<Symbol<'_>>>>,
    filename: Option<&Rt<Slot<Gc<&LispString>>>>,
    noerror: Option<()>,
    env: &mut Rt<Env<'_>>,
    cx: &'ob mut Context<'_>,
) -> Result<Symbol<'ob>>