read_ilang - read modules from ilang file

    read_ilang [filename]

Load modules from an ilang file to the current design. (ilang is a text
representation of a design in yosys's internal format.)

        ignore re-definitions of modules. (the default behavior is to
        create an error message if the existing module is not a blackbox
        module, and overwrite the existing module if it is a blackbox module.)

        overwrite existing modules with the same name

        only create empty blackbox modules