Proposal: add createPipe to base

[Herbert Valerio Riedel]

On 2014-03-10 at 13:30:05 +0100, Johan Tibell wrote:
> I've written a cross-platform* implementation of the pipe() syscall,
> currently for use within Cabal:
>
> createPipe :: IO (Handle, Handle)
> https://github.com/haskell/cabal/blob/master/Cabal/tests/Distribution/Compat/CreatePipe.hsc
>
> It's a bit of a shame to leave it in Cabal as it's generally useful.
>
> I propose we add it to System.IO. Note that we'd have to copy the 5 lines
> in System.Posix.IO.createPipe into base as the above implementation would
> otherwise depend on the unix package.

+1 from me (with a preference to put it in 'process' if that's still on the table)