Add empty placeholders to fix HIO funcs missing when linking debug version

src/d/actor/d_a_obj_ice.cpp

@@ -21,7 +21,7 @@ public:
     daObjIce_HIO_c();
     virtual ~daObjIce_HIO_c() {}
 
-    void genMessage(JORMContext* ctx);
+    void genMessage(JORMContext* ctx) {}
 
 public:
     /* 0x04 */ s8 mNo;