Make emulator thread time critical if possible on Windows to reduce fluctuations

src/qt/qt_main.cpp

@@ -437,6 +437,9 @@ main_thread_fn()
     int      frames;
 
     QThread::currentThread()->setPriority(QThread::HighestPriority);
+#ifdef _WIN32
+    SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_TIME_CRITICAL);
+#endif
     plat_set_thread_name(nullptr, "main_thread_fn");
     framecountx = 0;
     // title_update = 1;