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.
This is meant to replace heirloom yacc for compiling pre-musl parsers.
Unlike heirloom yacc, it's in the public domain, and can be linked with
meslibc without licensing concerns.