https://github.com/PLTools/Lama/blob/be0b32f7b9c75e61eff377cd34d4f65ebeeca204/runtime/runtime_common.h#L28 https://github.com/PLTools/Lama/blob/be0b32f7b9c75e61eff377cd34d4f65ebeeca204/runtime/runtime_common.h#L29 Is it suppose to be SEXP_HEADER_SZ (```(sizeof(int) + sizeof(size_t) + sizeof(int))```) in TO_SEXP?
