free-5: include/free-common.h

#ifndef MIN_VERSION_base
#define MIN_VERSION_base(x,y,z) 1
#endif

#ifndef MIN_VERSION_mtl
#define MIN_VERSION_mtl(x,y,z) 1
#endif

#if MIN_VERSION_base(4,9,0)
#define LIFTED_FUNCTOR_CLASSES 1
#else
#if MIN_VERSION_transformers(0,5,0)
#define LIFTED_FUNCTOR_CLASSES 1
#else
#if MIN_VERSION_transformers_compat(0,5,0) && !MIN_VERSION_transformers(0,4,0)
#define LIFTED_FUNCTOR_CLASSES 1
#endif
#endif
#endif