Add all the assignment code.

Signed-off-by: jmug <u.g.a.mariano@gmail.com>

hw4/oatprograms/lib5.oat

@@ -0,0 +1,9 @@
+int program (int argc, string[] argv) {
+  var str = "hello"; 
+  var arr = array_of_string (str);
+  var s = 0;
+  for (var i=0; i<5; i=i+1;) {
+    s = s + arr[i];
+  }
+  return s; 
+}