MSVC warnings

[vitaut]

    12>C:\projects\cppformat\test\posix-mock-test.cc(490): warning C4273: '_create_locale': inconsistent dll linkage [C:\projects\cppformat\test\posix-mock-test.vcxproj]
         C:\Program Files (x86)\Windows Kits\10\Include\10.0.10240.0\ucrt\locale.h(100): note: see previous definition of '_create_locale'
    12>C:\projects\cppformat\test\posix-mock-test.cc(494): warning C4273: '_free_locale': inconsistent dll linkage [C:\projects\cppformat\test\posix-mock-test.vcxproj]
         C:\Program Files (x86)\Windows Kits\10\Include\10.0.10240.0\ucrt\locale.h(105): note: see previous definition of '_free_locale'
    12>C:\projects\cppformat\test\posix-mock-test.cc(498): warning C4273: '_strtod_l': inconsistent dll linkage [C:\projects\cppformat\test\posix-mock-test.vcxproj]
         C:\Program Files (x86)\Windows Kits\10\Include\10.0.10240.0\ucrt\stdlib.h(499): note: see previous definition of '_strtod_l'

[vitaut]

Here are the declarations from locale.h (facepalm):

_Check_return_opt_
_ACRTIMP _locale_t __cdecl _create_locale(
    _In_   int         _Category,
    _In_z_ char const* _Locale
    );

_ACRTIMP void __cdecl _free_locale(
    _In_opt_ _locale_t _Locale
    );

[vitaut]

Fixed in 9ffe98c.