Converted PortReader and ChanWriter to use Vec.
auto merge of #14765 : rapha/rust/master, r=alexcrichton
rustc: Remove ~[T] from the language

The following features have been removed

* box [a, b, c]
* ~[a, b, c]
* box [a, ..N]
* ~[a, ..N]
* ~[T] (as a type)
* deprecated_owned_vector lint

All users of ~[T] should move to using Vec<T> instead.