build/byacc: Add a yacc-compatible parser generator

build/byacc: Add a yacc-compatible parser generator

From: Josef 'Jeff' Sipek <jeffpc@josefsipek.net>

Berkeley Yacc (byacc) is a Public Domain implementation.  The code it
creates is simple, and so it should be fairly easy to tailor it to
in-nucleus parser generation.  This code is based on the 20110908 version,
with several changes:

- replace autotools with cmake
- remove tests directory
- remove Windows & VMS build scripts

Signed-off-by: Josef 'Jeff' Sipek <jeffpc@josefsipek.net>