Now that "io" provides a method on object for stream-read-partial-unsafe that forwards to stream-read-unsafe, individual stream class that don't implement partial reads don't need to provide such a method themselves.
Now that all streams have been updated to implement the stream-read-unsafe protocol, take out the noncopying-reader shim. Turn stream-read and stream-read-partial into plain functions over the -unsafe generics.
Joe Groff
Doug Coleman
Slava Pestov