apache-orc: don't fail on warnings, at least outside -linux

https://hydra.nixos.org/build/324063460/nixlog/1/tail

I'm compromising for now to avoid rebuilding this on *-linux again,
but I honestly believe that this kind of warnings should not stop distro builds.
They should be hard errors only in upstream builds.

pkgs/by-name/ap/apache-orc/package.nix

@@ -66,7 +66,7 @@ stdenv.mkDerivation (finalAttrs: {
   cmakeFlags = [
     (lib.cmakeFeature "CMAKE_BUILD_TYPE" "Release")
     (lib.cmakeBool "BUILD_JAVA" false)
-    (lib.cmakeBool "STOP_BUILD_ON_WARNING" true)
+    (lib.cmakeBool "STOP_BUILD_ON_WARNING" stdenv.isLinux)
     (lib.cmakeBool "INSTALL_VENDORED_LIBS" false)
   ]
   ++ lib.optional (stdenv.hostPlatform != stdenv.buildPlatform) [