This makefile was included in the byacc distribution as Makefile.old
It was slightly updated to fit our needs.
Berkeley yacc itself is in the public domain, but SPDX/REUSE provides
no good way to represent this. In keeping with that spirit, I chose
CC0 as the license for my modifications, which SPDX can represent.
Unfortunatley the sha2 project does not have versioned releases so we
use the latest commit.
We have also manually added a frontend to sha-2 to allow us to invoke
it from the command line, thanks bittrof for the help!