QTextCodec::canEncode always returns true for codecForLocale() on Windows

QTextCodec::codecForLocale()->canEncode(string) seems to return `true` for any string I can give it, even those that it obviously fails to encode.

This seems to work properly for every other codec I tried.

I wouldn't be shocked if this impossible to handle correctly due to the way codecForLocale() has to be implemented on Windows, but if that's the case, it probably warrants a warning somewhere in the documentation.