undefine_finalizer

static VALUE
undefine_final(VALUE os, VALUE obj)
{
    rb_objspace_t *objspace = &rb_objspace;
    if (OBJ_FROZEN(obj)) rb_error_frozen("object");
    if (finalizer_table) {
        st_delete(finalizer_table, (st_data_t*)&obj, 0);
    }
    FL_UNSET(obj, FL_FINALIZE);
    return obj;
}