It says it only supports C89, and the largest type that C89 specifies is `long`, with a minimum size of 32 bits. So I presume it just doesn't provide `long lon

It says it only supports C89, and the largest type that C89 specifies is `long`, with a minimum size of 32 bits. So I presume it just doesn't provide `long long` (or `[u]int64_t`)