SDL: Store fake mouse warp event in virtual coordinates

Normally, notifyMousePosition converts real mouse events into the
virtual coordinate system, but events only get sent through
notifyMousePosition if they are real events from SDL since that
method also decides if the real mouse is inside the content area or
not. As such, these fake events need to be pre-converted to virtual
coordinates or else the wrong values are sent through to the engine
when a scaler or AR correction is in use.

backends/graphics/sdl/sdl-graphics.cpp

@@ -221,7 +221,8 @@ bool SdlGraphicsManager::notifyMousePosition(Common::Point &mouse) {
 void SdlGraphicsManager::setSystemMousePosition(const int x, const int y) {
 	assert(_window);
 	if (!_window->warpMouseInWindow(x, y)) {
-		_eventSource->fakeWarpMouse(x, y);
+		const Common::Point mouse = convertWindowToVirtual(x, y);
+		_eventSource->fakeWarpMouse(mouse.x, mouse.y);
 	}
 }