Function assign_register_token 

pub fn assign_register_token(
    cs: &Token,
    value: RegisterValue,
    scope: Option<Scope>,
    parameters: Vec<ArgWrap>,
) -> Result<()>

assign_register variant taking a pre-built Token — lets hot callers skip the T_CS!(&str) pin when they already have the CS cached (e.g. via T_CS!("\\c@…") literal which routes through pin!).