Function build_option 

pub fn build_option<'c, H: HugrView<Node = Node>>(
    ctx: &mut EmitFuncContext<'c, '_, H>,
    is_some: IntValue<'c>,
    some_value: BasicValueEnum<'c>,
    hugr_ty: HugrType,
) -> Result<BasicValueEnum<'c>>

Builds an optional value wrapping some_value conditioned on the provided is_some flag.