start working on runtime oop

src/memory.h

@@ -15,6 +15,7 @@
 void ar_finalizer(void *obj, GC_finalization_proc fn, void *client_data,
                   GC_finalization_proc *old_fn, void **old_client_data);
 void *ar_alloc(size_t size);
+void *ar_realloc(void * old,size_t size);
 void *ar_alloc_atomic(size_t size);
 char *ar_strdup(const char *str);