Ports: Add byacc port

Ports/byacc/package.sh

@@ -0,0 +1,5 @@
+#!/bin/bash ../.port_include.sh
+port=byacc
+version=20191125
+files="https://invisible-mirror.net/archives/byacc/byacc-20191125.tgz byacc-20191125.tgz"
+useconfigure=true

Ports/byacc/patches/fix-autoconf.patch

@@ -0,0 +1,10 @@
+--- byacc-20191125/config.sub.orig	Thu Jan 23 16:57:22 2020
++++ byacc-20191125/config.sub	Thu Jan 23 16:57:33 2020
+@@ -1339,6 +1339,7 @@
+ 	# Each alternative MUST end in a * to match a version number.
+ 	# sysv* is not here because it comes later, after sysvr4.
+ 	gnu* | bsd* | mach* | minix* | genix* | ultrix* | irix* \
++	     | serenity* \
+ 	     | *vms* | esix* | aix* | cnk* | sunos | sunos[34]*\
+ 	     | hpux* | unos* | osf* | luna* | dgux* | auroraux* | solaris* \
+ 	     | sym* | kopensolaris* | plan9* \

Ports/byacc/patches/fix-main.patch

@@ -0,0 +1,11 @@
+--- byacc-20191125/main.c.orig	Thu Jan 23 16:59:19 2020
++++ byacc-20191125/main.c	Thu Jan 23 16:59:29 2020
+@@ -7,6 +7,8 @@
+ #include <stdlib.h>		/* for _exit() */
+ #endif
+ 
++#include <getopt.h>
++
+ #include "defs.h"
+ 
+ #ifdef HAVE_MKSTEMP