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

src/d/actor/d_a_bb.cpp

@@ -73,7 +73,7 @@ public:
     }
     virtual ~bbHIO_c() {}
 
-    void genMessage(JORMContext* ctx);
+    void genMessage(JORMContext* ctx) {}
 
 public:
     /* 0x04 */ u8 unk_04;