This adds the ability to make a net.Conn based on a
reader/writer pair.
This is primarily useful for pretending stdin/stdout are a network
connection, but can be used for any reader/writer pair.
Change-Id: Ib398e62e0fac423db04aed27cfc48070bda2b93b
Reviewed-on: https://go-review.googlesource.com/c/tools/+/231697
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
