Add clearer win32 exception information in SplashScreen CreateWindow

[lindexi]

No description provided.

[ryalanms]

Thanks, @lindexi.

[lindexi]

Sorry, this pr is not needed. Because the Win32Exception will get the LastErrorCode when we create it without set the code.

    public Win32Exception()
      : this(Marshal.GetLastWin32Error())
    {
    }