cc-wrapper: disable response files for ccache

The problem is that the ccache wrapper does not work with response
files (it seems like the fd doesn't survive after exec in the
makeWrapper wrapper).

pkgs/build-support/cc-wrapper/default.nix

@@ -15,7 +15,7 @@
 , propagateDoc ? cc != null && cc ? man
 , extraTools ? [], extraPackages ? [], extraBuildCommands ? ""
 , nixSupport ? {}
-, isGNU ? false, isClang ? cc.isClang or false, gnugrep ? null
+, isGNU ? false, isClang ? cc.isClang or false, isCcache ? cc.isCcache or false, gnugrep ? null
 , buildPackages ? {}
 , libcxx ? null
 }:
@@ -178,7 +178,7 @@ stdenv.mkDerivation {
         local dst="$1"
         local wrapper="$2"
         export prog="$3"
-        export use_response_file_by_default=${if isClang then "1" else "0"}
+        export use_response_file_by_default=${if isClang && !isCcache then "1" else "0"}
         substituteAll "$wrapper" "$out/bin/$dst"
         chmod +x "$out/bin/$dst"
       }

pkgs/development/tools/misc/ccache/default.nix

@@ -76,6 +76,7 @@ let ccache = stdenv.mkDerivation rec {
       passthru = {
         isClang = unwrappedCC.isClang or false;
         isGNU = unwrappedCC.isGNU or false;
+        isCcache = true;
       };
       inherit (unwrappedCC) lib;
       nativeBuildInputs = [ makeWrapper ];