Revert "8145 - Mouse Position is unknown until first mouse event on X11 & Win"

This reverts commit e5d63aaece5310aee39ba1da9a595fc7a8410a50.
Same reasoning as #8291.

platform/windows/os_windows.cpp

@@ -2177,9 +2177,6 @@ void OS_Windows::run() {
 	if (!main_loop)
 		return;
 
-	// Process all events before the main initialization so the cursor will get initialized properly
-	process_events(); // get rid of pending events
-
 	main_loop->init();
 
 	uint64_t last_ticks = get_ticks_usec();

platform/x11/os_x11.cpp

@@ -1283,12 +1283,8 @@ void OS_X11::process_xevents() {
 
 				if (main_loop && mouse_mode != MOUSE_MODE_CAPTURED)
 					main_loop->notification(MainLoop::NOTIFICATION_WM_MOUSE_ENTER);
-				if (input) {
-					// Update mouse position. It is triggered before mouse motion.
-					Point2i pos(event.xmotion.x, event.xmotion.y);
-					input->set_mouse_pos(pos);
+				if (input)
 					input->set_mouse_in_window(true);
-				}
 			} break;
 			case FocusIn:
 				minimized = false;
@@ -1898,9 +1894,6 @@ void OS_X11::run() {
 	if (!main_loop)
 		return;
 
-	// Process all events before the main initialization so the cursor will get initialized properly
-	process_xevents(); // get rid of pending events
-
 	main_loop->init();
 
 	//	uint64_t last_ticks=get_ticks_usec();