dadadodo: fix darwin build

pkgs/tools/text/dadadodo/default.nix

···
     sha256 = "1pzwp3mim58afjrc92yx65mmgr1c834s1v6z4f4gyihwjn8bn3if";
   };
 
+  makeFlags = [ "CC=${stdenv.cc.targetPrefix}cc" ];
+
   installPhase = ''
     mkdir -p $out/bin
     cp dadadodo $out/bin
···
     description = "Markov chain-based text generator";
     homepage = "http://www.jwz.org/dadadodo";
     maintainers = with maintainers; [ pSub ];
-    platforms = with platforms; linux;
+    platforms = platforms.all;
   };
 }