Merge pull request #64 from Mr-Andersen/patch-1

Add os-string to "shipped with GHC" libraries

Author: cdepillabout

nix/build-support/stacklock2nix/default.nix

@@ -1001,13 +1001,15 @@ let
     ghc-boot-th = null;
     ghc-compact = null;
     ghc-heap = null;
+    ghc-internal = null;
     ghc-prim = null;
     ghci = null;
     haskeline = null;
     hpc = null;
     integer-gmp = null;
     libiserv = null;
     mtl = null;
+    os-string = null;
     parsec = null;
     pretty = null;
     process = null;