gcc49: 4.9.3 -> 4.9.4

Bugfix release of the 4.9 branch. See
http://lists.gnu.org/archive/html/info-gnu/2016-08/msg00001.html for
announcement

pkgs/development/compilers/gcc/4.9/default.nix

@@ -56,7 +56,7 @@ assert langGo -> langCC;
 with stdenv.lib;
 with builtins;
 
-let version = "4.9.3";
+let version = "4.9.4";
 
     # Whether building a cross-compiler for GNU/Hurd.
     crossGNU = cross != null && cross.config == "i586-pc-gnu";
@@ -213,7 +213,7 @@ stdenv.mkDerivation ({
 
   src = fetchurl {
     url = "mirror://gnu/gcc/gcc-${version}/gcc-${version}.tar.bz2";
-    sha256 = "0zmnm00d2a1hsd41g34bhvxzvxisa2l584q3p447bd91lfjv4ci3";
+    sha256 = "14l06m7nvcvb0igkbip58x59w3nq6315k6jcz3wr9ch1rn9d44bc";
   };
 
   inherit patches;