Give a reference to Foreign.Concurrent.
Give a reference to Foreign.Concurrent.

Test Plan: none

Reviewers: bgamari, austin, hvr

Reviewed By: bgamari

Subscribers: rwbarton, thomie

Differential Revision: https://phabricator.haskell.org/D4081

shlevy/ghc,ezyang/ghc,ezyang/ghc,shlevy/ghc,shlevy/ghc,sdiehl/ghc,sdiehl/ghc,sdiehl/ghc,ezyang/ghc,shlevy/ghc,sdiehl/ghc,ezyang/ghc,ezyang/ghc,sdiehl/ghc,sdiehl/ghc,sdiehl/ghc,shlevy/ghc,ezyang/ghc,shlevy/ghc,ezyang/ghc,shlevy/ghc