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/lib/tests/stdio/90-fread-fwrite.c

@@ -0,0 +1,79 @@
+/* -*-comment-start: "//";comment-end:""-*-
+ * GNU Mes --- Maxwell Equations of Software
+ * Copyright © 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/>.
+ */
+
+#include <mes/lib.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+int
+main ()
+{
+  char *temp = "COPYING.tmp";
+  char *new = "COPYING.new";
+
+  unlink (temp);
+  unlink (new);
+
+  FILE *t = fopen (temp, "wb+");
+  FILE *n = fopen (new, "wb");
+
+  char *header = "!<header>\n";
+  fwrite (header, strlen (header), 1, n);
+
+  char *data = "foo bar baz\n";
+  fwrite (data, strlen (data), 1, t);
+
+  fseek (t, 0, SEEK_END);
+  int size = ftell (t);
+  fprintf (stderr, "  size=>%d\n", size);
+  fseek (t, 0, SEEK_SET);
+  char *p = (char *) malloc (size + 1);
+  fread (p, size, 1, t);
+  fwrite (p, size, 1, n);
+
+  char header_plus_data[200];
+  strcpy (header_plus_data, header);
+  strcat (header_plus_data, data);
+
+  FILE *test = fopen (new, "r");
+  char buf[200];
+  fflush (n);
+  fread (buf, strlen (header_plus_data), 1, test);
+  eputs ("buf=");
+  eputs (buf);
+  eputs ("\n");
+  if (strcmp (buf, header_plus_data))
+    return 1;
+
+  if (access (temp, R_OK))
+    return 22;
+
+  unlink (temp);
+
+  if (!access (temp, R_OK))
+    return 3;
+
+  unlink (new);
+
+  return 0;
+}