Add all the assignment code.

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

hw6/hw5programs/ifq4.oat

@@ -0,0 +1,16 @@
+struct S { int x; int y }
+
+int sum(S? s) {
+    if?(S x = s) {
+      return x.x;
+    } else {
+      return 0;
+    }
+}
+
+int program (int argc, string[] argv) {
+    var x = 0;
+    x = x + sum(S null);
+    x = x + sum(new S{x=4; y=5});
+    return x;
+}