Add mes and mescc-tools-extra

mescc-tools-extra contains two important tools:
- cp
- chmod

mes first builds itself from a mes 0.21 seed as used by guix, and then
builds a mes 0.22 and then mes 0.22 using that created mes 0.22.

It does /not/ use bootstrap.sh as we don't have a proper shell at this
point, it has been manually adapted for kaem.

sysa/mes-0.22/build-aux/build-source-lib.sh

@@ -0,0 +1,53 @@
+#! /bin/sh
+
+# GNU Mes --- Maxwell Equations of Software
+# Copyright © 2019 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
+#
+# This file is part of GNU Mes.
+#
+# GNU Mes is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or (at
+# your option) any later version.
+#
+# GNU Mes is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GNU Mes.  If not, see <http://www.gnu.org/licenses/>.
+
+set -e
+
+if test "$V" = 2; then
+    set -x
+fi
+
+set -u
+srcdest=${srcdest-}
+. ${srcdest}build-aux/configure-lib.sh
+
+mkdir -p $mes_cpu-mes
+cp ${srcdest}lib/$mes_kernel/$mes_cpu-mes-$compiler/crt*.c $mes_cpu-mes
+
+rm -f libc+gnu.c
+cat > libc+gnu.c <<EOF
+// Generated from Mes -- do not edit
+// compiler: $compiler
+// cpu:      $mes_cpu
+// bits:     $mes_bits
+// libc:     $mes_libc
+// kernel:   $mes_kernel
+// system:   $mes_system
+
+EOF
+for c in $libc_gnu_SOURCES; do
+    echo "// $c" >> libc+gnu.c
+    cat ${srcdest}$c >> libc+gnu.c
+    echo >> libc+gnu.c
+done
+cp libc+gnu.c $mes_cpu-mes
+
+cp ${srcdest}lib/libtcc1.c $mes_cpu-mes
+cp ${srcdest}lib/posix/getopt.c $mes_cpu-mes/libgetopt.c