byacc: 20180510 -> 20180525 (#41304)

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
- /nix/store/bz6434x282zsy6xz19nbd3fhzmdr4yzy-byacc-20180525/bin/yacc passed the binary check.
- 1 of 1 passed binary check by having a zero exit code.
- 0 of 1 passed binary check by having the new version present in output.
- found 20180525 with grep in /nix/store/bz6434x282zsy6xz19nbd3fhzmdr4yzy-byacc-20180525
- directory tree listing: https://gist.github.com/fffd356f1d450bf13fc3f2bf8a8f5304
- du listing: https://gist.github.com/3e8f1a51d1e20db022ff93cedc85b5a7