We propose to remove the following exports from GHC.Exts:

data IOPort# s a
newIOPort# :: State# s -> (# State# s, IOPort# s o #)
readIOPort# :: IOPort# s o -> State# s -> (# State# s, o #)
writeIOPort# :: IOPort# s o -> o -> State# s -> (# State# s, Int# #)

These expose the IOPort# type used internally to implement WinIO. The semantics of this type are not of use to end users and there are no users on Hackage. We intend to remove this type from GHC as it is no longer used.