On Windows, we can't just look up a FD for libuv streams and
return it in `GetFD()`.
However, we do sometimes construct streams from their FDs;
in those cases, it should be okay to store the value on a class field.

PR-URL: #19377
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>

This currently crashes during environment cleanup because
the object would be torn down while there are enabled categories.

I’m not sure about the exact semantics here, but since the
object cannot be garbage collected at this point anyway
because it’s `Persistent` handle is strong, removing the
destructor at least doesn’t make anything worse than it is
right now (i.e. the destructor would never have been called
before anyway).

PR-URL: #19377
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>

This is done to match the stream implementation, which also
only actually stops reading in the next tick after the `'pause'`
event is emitted.

PR-URL: #19377
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>

For libuv-backed streams, always explicitly stop reading before
closing the handle.

PR-URL: #19377
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>

Instead of using the libuv mechanism directly, provide an internal
`ThreadPoolWork` wrapper that takes care of increasing/decreasing
the waiting request counter.

PR-URL: #19377
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>

Refs: #19377
PR-URL: #20585
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>