java: examples: split in two

* examples/java: Split in...
* examples/java/simple, examples/java/calc: these.

examples/java/simple/Calc.test

@@ -0,0 +1,33 @@
+#! /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 = 7
+(1 + 2) * 3 = 9
+EOF
+run 0 '7
+9'
+
+cat >input <<EOF
+1 + 2 * * 3
+EOF
+run 0 "err: syntax error, unexpected '*', expecting number or '-' or '(' or '!'"