Arbitrary precision integers

[kvverti]

Make Lavender support arbitrary precision integral arithmetic. Practically something like this, where data is stored in little-endian order. The struct shown below can theoretically store 2^70 bits (128 EiB), which is far larger than any personal computer can handle.

struct LvInt {
    size_t refCount;
    size_t len;
    uint64_t data[];
};