The errors are related with _cdecl and _stdcall.
With the changes below, the compilation are ok:
#if defined( HB_OS_WIN ) || defined( HB_OS_OS2 )
#ifdef __cplusplus
#define HB_CDECL __cdecl
#else
#define HB_CDECL _cdecl
#endif
#else
#define HB_CDECL
#endif
...
#if defined( HB_OS_WIN )
#ifdef __cplusplus
HB_DYN_CTYPE_DECL( HB_U32, __stdcall, FX86_S32 );
HB_DYN_CTYPE_DECL( HB_U64, __stdcall, FX86_S64 );
HB_DYN_CTYPE_DECL( double, __stdcall, FX86_SDB );
HB_DYN_CTYPE_DECL( float, __stdcall, FX86_SFL );
#else
HB_DYN_CTYPE_DECL( HB_U32, _stdcall, FX86_S32 );
HB_DYN_CTYPE_DECL( HB_U64, _stdcall, FX86_S64 );
HB_DYN_CTYPE_DECL( double, _stdcall, FX86_SDB );
HB_DYN_CTYPE_DECL( float, _stdcall, FX86_SFL );
#endif
#endif
Regards,
Marcos Gambeta