[commit: ghc] master: Update unix submodule to latest 2.7.1.0 snapshot (b317904)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/b31790487b191055bce53aff8707b35efb5835ef/ghc

>---------------------------------------------------------------

commit b31790487b191055bce53aff8707b35efb5835ef
Author: Herbert Valerio Riedel <hvr at gnu.org>
Date:   Mon Dec 15 23:36:06 2014 +0100

    Update unix submodule to latest 2.7.1.0 snapshot


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b31790487b191055bce53aff8707b35efb5835ef
 libraries/unix | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libraries/unix b/libraries/unix
index 256b191..757bf44 160000
--- a/libraries/unix
+++ b/libraries/unix
@@ -1 +1 @@
-Subproject commit 256b19184bcb05c3cd9a6061730b7d67d61c0763
+Subproject commit 757bf44bb4895fc561a2e5dd2f602168478741ec