Extract /Sanity/build-java-project out of /Sanity/smoke

/Sanity/smoke is intended to work with all possible Java versions,
JDK, JRE, or even minimal Java installations created with jlink.

Sanity/build-java-project/src/main/java/tt/My.java

@@ -0,0 +1,28 @@
+package tt;
+
+/** Very sophisticated functionality.
+    @author Mikolaj Izdebski
+*/
+public class My {
+    /** Some non-trivial code here.
+        @param x first substrate
+        @param y second substrate
+        @return sum of the two
+     */
+    public int add(int x, int y) {
+        return x + y;
+    }
+
+    /** Maint entry point.
+        @arg args string arguments
+    */
+    public static void main(String[] args) {
+        String s1 = args[0];
+        String s2 = args[1];
+        int i1 = Integer.parseInt(s1);
+        int i2 = Integer.parseInt(s2);
+        My adder = new My();
+        int result = adder.add(i1, i2);
+        System.out.println("RESULT is " + result);
+    }
+}