Fix: missing abstract defs in Crystal::EventLoop::Socket interface

src/crystal/event_loop/socket.cr

@@ -15,6 +15,9 @@ abstract class Crystal::EventLoop
     # Use `#receive_from` for capturing the source address of a message.
     abstract def read(socket : ::Socket, slice : Bytes) : Int32
 
+    # Blocks the current fiber until the socket is ready for read.
+    abstract def wait_readable(socket : ::Socket) : Nil
+
     # Writes at least one byte from *slice* to the socket.
     #
     # Blocks the current fiber if the socket is not ready for writing,
@@ -25,6 +28,9 @@ abstract class Crystal::EventLoop
     # Use `#send_to` for sending a message to a specific target address.
     abstract def write(socket : ::Socket, slice : Bytes) : Int32
 
+    # Blocks the current fiber until the socket is ready for write.
+    abstract def wait_writable(socket : ::Socket) : Nil
+
     # Accepts an incoming TCP connection on the socket.
     #
     # Blocks the current fiber if no connection is waiting, continuing when one