Move heirloom lex and flex after musl, replace heirloom yacc with byacc

This way, heirloom-devtools is only linked to a libc with a CDDL-compatible
license, making it fully redistributable. Heirloom yacc doesn't work properly
with musl libc, but luckily byacc can do its job just fine, so we only need
heirloom lex now.

Thanks to the more complete libc, and bash being available, heirloom's
bootstrap is significantly simplified.

steps/heirloom-devtools-070527/pass1.sh

@@ -0,0 +1,21 @@
+#!/bin/sh
+
+# SPDX-FileCopyrightText: 2021 Andrius Štikonas <andrius@stikonas.eu>
+# SPDX-FileCopyrightText: 2021-22 fosslinux <fosslinux@aussies.space>
+# SPDX-FileCopyrightText: 2024 Gábor Stefanik <netrolller.3d@gmail.com>
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+src_compile() {
+    cd lex
+    make -f Makefile.mk CC=tcc AR=tcc\ -ar LDFLAGS=-static RANLIB=true
+    cd ..
+}
+
+src_install() {
+    mkdir -p "${DESTDIR}${BINDIR}" "${DESTDIR}${LIBDIR}/lex"
+    install lex/lex "${DESTDIR}${BINDIR}"
+    install lex/libl.a "${DESTDIR}${LIBDIR}"
+    install -m 644 lex/ncform "${DESTDIR}${LIBDIR}/lex"
+}
+