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/tests/let.test

@@ -0,0 +1,67 @@
+#! /bin/sh
+# -*-scheme-*-
+exec ${MES-bin/mes} --no-auto-compile -L ${0%/*} -L module -C module -e '(tests let)' -s "$0" "$@"
+!#
+
+;;; -*-scheme-*-
+
+;;; GNU Mes --- Maxwell Equations of Software
+;;; Copyright © 2016,2018 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/>.
+
+(define-module (tests let)
+  #:use-module (mes mes-0)
+  #:use-module (mes test))
+
+(mes-use-module (mes let))
+(mes-use-module (mes test))
+
+(pass-if "first dummy" #t)
+(pass-if-not "second dummy" #f)
+
+(pass-if-equal "let " 1
+  (let ((x 1)) 1))
+
+(let () (define *let-define* '*let-define*) #f)
+(pass-if-equal "let define "
+    #f
+    (and (defined? '*let-define*) *let-define*))
+
+(begin (define *begin-define* '*begin-define*) #f)
+(pass-if-equal "begin define" '*begin-define*
+               (and (defined? '*begin-define*) *begin-define*))
+
+(pass-if-equal "let loop" '(3 2 1)
+  (let loop ((lst '(3 2 1)))
+    (cond ((null? lst) '())
+          (#t (cons (car lst) (loop (cdr lst)))))))
+
+(pass-if-equal "let* comments" 5
+  (let* ((aa 2)
+         (bb (+ aa 3))
+         #! boo !#
+         ;;(bb 4)
+         )
+    bb))
+
+(pass-if-equal "letrec" 24
+  (letrec ((factorial (lambda (n)
+                        (cond ((= n 1) 1)
+                              (#t (* n (factorial (- n 1))))))))
+    (factorial 4)))
+
+(result 'report)