Returns true if the type is a link

Property definitions

core $ NativeFileStat :: is_lnk
	# Returns true if the type is a link
	fun is_lnk: Bool `{
#ifdef _WIN32
	return 0;
#else
	return S_ISLNK(self->st_mode);
#endif
	`}
lib/core/file.nit:1495,2--1502,3