xcbuild: temporarily fix cflags/ldflags

This gets everything to build.

adv_cmds: remove NIX_LDFLAGS

- unneeded

pkgs/development/tools/xcbuild/setup-hook.sh

@@ -3,7 +3,7 @@ xcbuildPhase() {
 
     echo "running xcodebuild"
 
-    xcodebuild OTHER_CFLAGS="$NIX_CFLAGS_COMPILE"
+    xcodebuild
 
     runHook postConfigure
 }

pkgs/os-specific/darwin/apple-source-releases/adv_cmds/xcode.nix

@@ -14,7 +14,7 @@ stdenv.mkDerivation {
   '';
 
   buildInputs = [ xcbuild libcxx ];
-  #NIX_CFLAGS_COMPILE = stdenv.lib.optionalString stdenv.isDarwin "-I${libcxx}/include/c++/v1";
+  NIX_CFLAGS_COMPILE = stdenv.lib.optionalString stdenv.isDarwin "-I${libcxx}/include/c++/v1";
 
   meta = {
     platforms = stdenv.lib.platforms.darwin;