Fix suffixSalt calculation

Author: hamishmack

compiler/ghc/default.nix

@@ -400,7 +400,7 @@ stdenv.mkDerivation (rec {
         # windows gcc cross compiler has a full `windows.h`).
         # This matches the way `suffixSalt` is calculated in nixpkgs.
         # See https://github.com/NixOS/nixpkgs/blob/8411006d6bcd7f6e6a8a1a80ce8fcdccdd16c6ab/pkgs/build-support/cc-wrapper/default.nix#L58
-        replaceStrings ["-" "."] ["_" "_"] stdenv.hostPlatform.config
+        lib.replaceStrings ["-" "."] ["_" "_"] stdenv.hostPlatform.config
       }+=" -I${../windows/include}"
     if [[ -f libraries/base/include/winio_structs.h ]]; then
       substituteInPlace libraries/base/include/winio_structs.h --replace Windows.h windows.h