build-macos: fix SDL input poll crash

macOS kills apps that interact with the UX
from anything but the main thread. Let the frontend
handle the inputs on macOS so this doesn't happen.

src/input_common/drivers/sdl_driver.cpp

@@ -419,7 +419,13 @@ SDLDriver::SDLDriver(std::string input_engine_) : InputEngine(std::move(input_en
     SDL_SetHint(SDL_HINT_JOYSTICK_HIDAPI_XBOX, "0");
 
     // If the frontend is going to manage the event loop, then we don't start one here
+#ifdef __APPLE__
+    // macOS will crash the application if any thread but the main one
+    // tries to interact with the UX in any way.
+    start_thread = false;
+#else
     start_thread = SDL_WasInit(SDL_INIT_JOYSTICK | SDL_INIT_GAMECONTROLLER) == 0;
+#endif
     if (start_thread && SDL_Init(SDL_INIT_JOYSTICK | SDL_INIT_GAMECONTROLLER) < 0) {
         LOG_CRITICAL(Input, "SDL_Init failed with: {}", SDL_GetError());
         return;

src/yuzu/main.cpp

@@ -296,7 +296,11 @@ GMainWindow::GMainWindow()
     ui->action_Fullscreen->setChecked(false);
 
 #if defined(HAVE_SDL2) && !defined(_WIN32)
+#ifdef __APPLE__
+    SDL_InitSubSystem(SDL_INIT_VIDEO | SDL_INIT_JOYSTICK | SDL_INIT_GAMECONTROLLER);
+#else
     SDL_InitSubSystem(SDL_INIT_VIDEO);
+#endif
     // SDL disables the screen saver by default, and setting the hint
     // SDL_HINT_VIDEO_ALLOW_SCREENSAVER doesn't seem to work, so we just enable the screen saver
     // for now.