[MISC] Allow user to override process priority class

src/xenia/emulator.cc

@@ -86,6 +86,12 @@ DECLARE_int32(user_language);
 
 DECLARE_bool(allow_plugins);
 
+DEFINE_int32(priority_class, 0,
+             "Forces Xenia to use different process priority than default one. "
+             "It might affect performance and cause unexpected bugs. Possible "
+             "values: 0 - Normal, 1 - Above normal, 2 - High",
+             "General");
+
 namespace xe {
 using namespace xe::literals;
 
@@ -125,6 +131,13 @@ Emulator::Emulator(const std::filesystem::path& command_line,
       paused_(false),
       restoring_(false),
       restore_fence_() {
+  if (cvars::priority_class != 0) {
+    if (SetProcessPriorityClass(cvars::priority_class)) {
+      XELOGI("Higher priority class request: Successful. New priority: {}",
+             cvars::priority_class);
+    }
+  }
+
 #if XE_PLATFORM_WIN32 == 1
   // Show a disclaimer that links to the quickstart
   // guide the first time they ever open the emulator