[commit: ghc] master: Improve detection of `fdatasync(2)` (re #11137) (ab79ed7)

[git at git.haskell.org]

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

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/ab79ed763cfbaa1b0d1f39ba5ed1cde7dffd4b87/ghc

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commit ab79ed763cfbaa1b0d1f39ba5ed1cde7dffd4b87
Author: Herbert Valerio Riedel <hvr at gnu.org>
Date:   Wed Dec 16 17:40:48 2015 +0100

    Improve detection of `fdatasync(2)` (re #11137)
    
    This updates the `unix` submodule to pull in an improved
    Autoconf test for `fdatasync(2)` in cases where `<unistd.h>` lacks
    a declaration, but linking against `fdatasync` works which led to a
    false positive previously.


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ab79ed763cfbaa1b0d1f39ba5ed1cde7dffd4b87
 libraries/unix | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libraries/unix b/libraries/unix
index 59edb0a..5d5b747 160000
--- a/libraries/unix
+++ b/libraries/unix
@@ -1 +1 @@
-Subproject commit 59edb0a0a0d91ecfe938029b3b00a0c99dcb8481
+Subproject commit 5d5b74716b696b0f22c37a88ccc5c114b13f0398