Function hard_verilog_for 

pub fn hard_verilog_for(
    op: Op,
    module: &str,
    block: &Block,
    latency: usize,
    target: &Semantics,
) -> Result<String, HardError>

hard_verilog computing target (plan_for): hard_verilog is this of Semantics::ENGINE, byte for byte.