[Bug go/67874] fd_unix.go does not build when there is fcntl64 and no fcntl syscall

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67874

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Note I think tilegx32 target might have the same issue as it uses the new
generic syscall interface and there is no fcntl there either.