Final (hopefully) fix for the build bots.

This time it actually occurred to me to change the #defines
to actually test the pre-processed out codepath.  Hopefully
this time it works.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@302752 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Support/Parallel.cpp

@@ -117,7 +117,7 @@ private:
   std::stack<std::function<void()>> WorkStack;
   std::mutex Mutex;
   std::condition_variable Cond;
-  detail::Latch Done;
+  parallel::detail::Latch Done;
 };
 
 Executor *Executor::getDefaultExecutor() {