0.8.0

Windows. aviancore builds and passes its tests natively on Windows 10 and
later (x86-64, Swift 6.3, MSVC, OpenSSL 3 or 4), and Peregrine serves on it.
The API changes it needs are why this is 0.8.0, not 0.7.4; on Linux and
macOS nothing a caller compiles against changes type.

• A socket is av_sock (AvianSocket in Swift) and a poller is
  av_poll_t (AvianPollHandle). Both are int on POSIX, so Swift still
  sees Int32 there. On Windows a socket is a SOCKET, which is unsigned and
  pointer-sized: test it with isSocket(s) (C: av_sock_ok) and use
  noSocket (C: av_bad_sock, AV_BAD_SOCK) where -1 was, because
  fd >= 0 is always true there and still compiles.
• Files are not sockets. Use av_read_file and av_close_file for a
  descriptor from av_static_open and the like; av_read and av_close are
  socket calls on Windows. av_write_stdout and av_write_stderr write the
  standard streams, which av_write(1 or 2, ...) cannot on Windows; Log
  uses them.
• Functions that returned or took long take ssize_t: av_tls_read,
  av_tls_write, av_tls_sendfile, av_udp_send, av_udp_send_segments,
  av_read_stamped, av_send_fd, av_recv_fd, av_cache_init,
  av_raise_nofile_limit and the av_aead_*, av_kex_* and av_certkey_*
  calls. long is 32 bits on Windows; Swift sees Int on every platform now.
• Worker processes without fork: av_spawn_self. It starts this program
  again with this command line, handing the copy a list of sockets and every
  region av_shm_map has made, and keeps a control socket to it: av_kill
  with any signal but 0 and 9 writes the number there, which the child reads
  from av_signal_pipe_init, and av_waitpid(-1, ...) reaps these children.
  A job object ends them with the parent. In the child, av_spawned gives
  the role it was started with, av_spawned_sockets the sockets (in
  non-blocking mode, which Winsock does not carry across), and av_shm_map
  maps the inherited regions in order; av_shm_attached says a region was
  inherited, and the cache, rate-limit, load and metrics tables keep their
  contents and seeds when it was. POSIX keeps forking; there av_spawn_self
  fails with ENOSYS.
• The Windows backends. wepoll 1.5.8 is the poller (vendored, epoll's
  API over AFD, level-triggered); pipes are loopback socket pairs because it
  watches sockets only; console control events are the signals (Ctrl-C is
  SIGINT, the rest SIGTERM); static files are opened, then checked to resolve
  inside the root, which is what openat2 guarantees on Linux; --reload
  watches with ReadDirectoryChangesW; UDP carries PKTINFO and ECN through
  WSARecvMsg and WSASendMsg; zlib 1.3.2 is vendored as CAvianZlib, built on
  Windows only.
• New portable helpers: av_sleep_ms, av_dir_open/av_dir_next/
  av_dir_close, av_shm_map/av_shm_unmap (used by every shared table),
  av_process_alive, av_yield, av_entropy64. Poller exposes its event
  array (eventBuffer, eventCapacity) for a caller that waits on another
  thread.
• The cache table's seed lives in its header and the rate limiter's in an
  entry in front of its table, so a process that maps them later hashes
  alike. Neither layout is visible to callers.
• Not on Windows yet: UDP segmentation offload (datagrams are sent one at a
  time), TransmitFile (static files are read and sent), BoringSSL's
  assembly (SwiftPM cannot build its NASM sources, so TLS there is the
  portable C, as in swift-nio-ssl), and av_execv, av_fork* and descriptor
  passing, which fail with ENOSYS.