Revert removal of Teardown call

As per review recommendation.

Common/Thread/ThreadManager.cpp

@@ -98,6 +98,10 @@ static void WorkerThreadFunc(GlobalThreadContext *global, ThreadContext *thread)
 }
 
 void ThreadManager::Init(int numRealCores, int numLogicalCoresPerCpu) {
+	if (!global_->threads_.empty()) {
+		Teardown();
+	}
+
 	numComputeThreads_ = std::min(numRealCores * numLogicalCoresPerCpu, MAX_CORES_TO_USE);
 	int numThreads = numComputeThreads_ + EXTRA_THREADS;
 	numThreads_ = numThreads;