Function lseek64_compat

cpp/src/arrow/util/io_util.cc:1043–1053

int FileDescriptor::Detach() { return fd_.exchange(-1); }

static Result<int64_t> lseek64_compat(int fd, int64_t pos, int whence) {
#if defined(_WIN32)
  int64_t ret = _lseeki64(fd, pos, whence);
#else
  int64_t ret = lseek(fd, pos, whence);
#endif
  if (ret == -1) {
    return Status::IOError("lseek failed");
  }
  return ret;
}

Result<FileDescriptor> FileOpenReadable(const PlatformFilename& file_name) {
  FileDescriptor fd;