byacc: 20170709 -> 20180510 (#40499)

Semi-automatic update generated by https://github.com/ryantm/nixpkgs-update tools.

This update was made based on information from https://repology.org/metapackage/byacc/versions.

These checks were done:

- built on NixOS
- Warning: no binary found that responded to help or version flags. (This warning appears even if the package isn't expected to have binaries.)
- found 20180510 with grep in /nix/store/z8i5f145zpz750hvcbjlncy8kqak8zv2-byacc-20180510
- directory tree listing: https://gist.github.com/328d2b1900cfb911e7567cabf95d80c3
- du listing: https://gist.github.com/cc161fe31193017387ae25b64829aaf2