[wpinet] TCPConnector_parallel: Don't use thread_local (#5791)

Thread_local causes issues with LabVIEW, which makes calls on a thread
pool.

wpinet/src/main/native/thirdparty/tcpsockets/cpp/TCPConnector_parallel.cpp

@@ -15,14 +15,6 @@
 
 using namespace wpi;
 
-// MSVC < 1900 doesn't have support for thread_local
-#if !defined(_MSC_VER) || _MSC_VER >= 1900
-// clang check for availability of thread_local
-#if !defined(__has_feature) || __has_feature(cxx_thread_local)
-#define HAVE_THREAD_LOCAL
-#endif
-#endif
-
 std::unique_ptr<NetworkStream> TCPConnector::connect_parallel(
     std::span<const std::pair<const char*, int>> servers, Logger& logger,
     int timeout) {
@@ -33,18 +25,10 @@ std::unique_ptr<NetworkStream> TCPConnector::connect_parallel(
   // structure to make sure we don't start duplicate workers
   struct GlobalState {
     wpi::mutex mtx;
-#ifdef HAVE_THREAD_LOCAL
-    SmallSet<std::pair<std::string, int>, 16> active;
-#else
     SmallSet<std::tuple<std::thread::id, std::string, int>, 16> active;
-#endif
   };
-#ifdef HAVE_THREAD_LOCAL
-  thread_local auto global = std::make_shared<GlobalState>();
-#else
   static auto global = std::make_shared<GlobalState>();
   auto this_id = std::this_thread::get_id();
-#endif
   auto local = global;  // copy to an automatic variable for lambda capture
 
   // structure shared between threads and this function
@@ -63,12 +47,8 @@ std::unique_ptr<NetworkStream> TCPConnector::connect_parallel(
   for (const auto& server : servers) {
     std::pair<std::string, int> server_copy{std::string{server.first},
                                             server.second};
-#ifdef HAVE_THREAD_LOCAL
-    const auto& active_tracker = server_copy;
-#else
     std::tuple<std::thread::id, std::string, int> active_tracker{
         this_id, server_copy.first, server_copy.second};
-#endif
 
     // don't start a new worker if we had a previously still-active connection
     // attempt to the same server