为什么微软要定义如此多的别名？

到处都是，编写最简单的窗口程序，前向声明窗口过程函数：
LRESULT CALLBACK WinSunProc(                       // long long int
    HWND hwnd,                                     // HWND__*
    UINT uMsg,                                       // unsigned int
    WPARAM wParam,                                   // unsigned int
    LPARAM lParam                                    // long int
);
微软这么干是简化了开发还是画蛇添足？