Function gguf_string_size

gguf-tools/deepseek4-quantize.c:1399–1401

static byte_buf i64_to_i32(const st_value *src) {
    if (strcmp(src->dtype, "I64") != 0) die("expected I64 source for I32 tensor");
    const int64_t n = value_nelements(src);
    if (src->nbytes != (size_t)n * sizeof(int64_t)) die("bad I64 byte size");
    byte_buf out = { .size = (size_t)n * sizeof(int32_t), .data = xmalloc((size_t)n * sizeof(int32_t)) };
    int32_t *dst = (int32_t *)out.data;
    for (int64_t i = 0; i < n; i++) {