boost.spawn: review requested

From: Oliver Kowalke (oliver.kowalke_at_[hidden])
Date: 2021-11-28 06:49:43

Hi,
I'd like to propose the new library boost.spawn (https://olk.github.io/)
for review.
boost.asio's boost::asio::spawn() uses the deprecated and inefficient
boost.coroutine library.
boost.spawn provides the same functionality while using boost.context's
fiber directly.

Oliver