examples: d: duplicate the example as "simple" and "calc"

* examples/d/Makefile, examples/d/calc.d, examples/d/calc.test,
examples/d/calc/local.mk: Move into...
* examples/d/calc, examples/d/simple: these new directories.

examples/d/simple/calc.test

@@ -0,0 +1,36 @@
+#! /bin/sh
+
+# Copyright (C) 2018-2020 Free Software Foundation, Inc.
+#
+# This program 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.
+#
+# This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+
+cat >input <<EOF
+1 + 2 * 3
+EOF
+run 0 7
+
+cat >input <<EOF
++1 + +2 * +3
+EOF
+run 0 7
+
+cat >input <<EOF
+-1 + -2 * -3
+EOF
+run 0 5
+
+cat >input <<EOF
+1 + 2 * * 3
+EOF
+run 1 "err: syntax error, unexpected *, expecting + or - or ( or number"