Change hw6 to an unsolved version.

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

hw6/hw5programs/tc_subtyping8.oat

@@ -13,7 +13,7 @@ void g((C) -> B f) {
   return;
 }
 
-int program(string[] args) {
+int program(int argc, string[] args) {
   g(f);
   return 0;
 }