Move threading utils from native to Common

Common/Thread/Executor.cpp

@@ -0,0 +1,23 @@
+#include "Common/Thread/Executor.h"
+
+#include <functional>
+#include <thread>
+
+namespace threading {
+
+void SameThreadExecutor::Run(std::function<void()> func) {
+	func();
+}
+
+void NewThreadExecutor::Run(std::function<void()> func) {
+	threads_.push_back(std::thread(func));
+}
+
+NewThreadExecutor::~NewThreadExecutor() {
+	// If Run was ever called...
+	for (auto &thread : threads_)
+		thread.join();
+	threads_.clear();
+}
+
+}  // namespace threading