Merge staging into closure-size

The most complex problems were from dealing with switches reverted in
the meantime (gcc5, gmp6, ncurses6).
It's likely that darwin is (still) broken nontrivially.

pkgs/tools/security/tor/torbrowser.nix

@@ -2,9 +2,6 @@
 , xorg, alsaLib, dbus, dbus_glib, glib, gtk, atk, pango, freetype, fontconfig
 , gdk_pixbuf, cairo, zlib}:
 let
-  bits = if stdenv.system == "x86_64-linux" then "64"
-         else "32";
-
   # isolated tor environment
   torEnv = buildEnv {
     name = "tor-env";
@@ -15,18 +12,17 @@ let
     ];
   };
 
-  ldLibraryPath = if bits == "64" then torEnv+"/lib:"+torEnv+"/lib64"
-        else torEnv+"/lib";
+  ldLibraryPath = ''${torEnv}/lib${stdenv.lib.optionalString stdenv.is64bit ":${torEnv}/lib64"}'';
 
 in stdenv.mkDerivation rec {
   name = "tor-browser-${version}";
-  version = "4.5.3";
+  version = "5.0.4";
 
   src = fetchurl {
-    url = "https://archive.torproject.org/tor-package-archive/torbrowser/${version}/tor-browser-linux${bits}-${version}_en-US.tar.xz";
-    sha256 = if bits == "64" then
-      "24c517d2aeb15ba5eeda1eb87f483ed4fb0c22b07a95ca26af9f692e0d4d9b7c" else
-      "154d659583048e91870c40921561f0519babf6d3c9ac439f6fb74ed66824463f";
+    url = "https://archive.torproject.org/tor-package-archive/torbrowser/${version}/tor-browser-linux${if stdenv.is64bit then "64" else "32"}-${version}_en-US.tar.xz";
+    sha256 = if stdenv.is64bit then
+      "03vn1wkkpgr6wzd6iiyqs7zv7yxl9q99j755n8l2579bd10w1xcn" else
+      "1yc13cykr4fafz6r8hnjccl0s33sk297c779cknbdbhj3z3yn163";
   };
 
   patchPhase = ''