WCHAR_MIN and WCHAR_MAX missing guards in stdint.h

[Thomas Uhle]

Hello,

the definitions WCHAR_MIN and WCHAR_MAX are not protected by #ifndef ...
in stdint.h like they are in wchar.h. Therefore, GCC outputs warnings
about doubled definitions during compilation if wchar.h and stdint.h are
both included. I think a possible fix would be to adopt the code in
stdint.h w.r.t. wchar.h.

Regards,

Thomas Uhle