Change occurrences of gcc to the more general cc

This is done for the sake of Yosemite, which does not have gcc, and yet
this change is also compatible with Linux.

pkgs/tools/security/tor/torbrowser.nix

@@ -9,7 +9,7 @@ let
   torEnv = buildEnv {
     name = "tor-env";
     paths = [
-      stdenv.gcc.gcc zlib glib alsaLib dbus dbus_glib gtk atk pango freetype
+      stdenv.cc.gcc zlib glib alsaLib dbus dbus_glib gtk atk pango freetype
       fontconfig gdk_pixbuf cairo xlibs.libXrender xlibs.libX11 xlibs.libXext
       xlibs.libXt
     ];
@@ -30,8 +30,8 @@ in stdenv.mkDerivation rec {
   };
 
   patchPhase = ''
-    patchelf --set-interpreter "$(cat $NIX_GCC/nix-support/dynamic-linker)" Browser/firefox
-    patchelf --set-interpreter "$(cat $NIX_GCC/nix-support/dynamic-linker)" Browser/TorBrowser/Tor/tor
+    patchelf --set-interpreter "$(cat $NIX_CC/nix-support/dynamic-linker)" Browser/firefox
+    patchelf --set-interpreter "$(cat $NIX_CC/nix-support/dynamic-linker)" Browser/TorBrowser/Tor/tor
   '';
 
   doCheck = true;