How to incorporate ipc::channel with asio

[jbbjarnason]

On Linux, is it possible to get a file descriptor for a ipc::channel to assign to asio::posix::stream_descriptor? So I could let asio handle epoll for that given file descriptor and await new events from the ipc::channel, such as receive.

For reference, https://think-async.com/Asio/asio-1.22.0/doc/asio/reference/posix__stream_descriptor.html

[mutouyun]

I will carefully consider this issue in the refactoring branch.