[Bug libstdc++/67114] [MinGW64] build failure with POSIX threads enabled

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67114

--- Comment #16 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Jonathan Wakely from comment #15)
>        friend bool
>        operator<(thread::id __x, thread::id __y) noexcept
> -      { return __x._M_thread < __y._M_thread; }
> -
> +      {	return __less<native_handle_type>::_S_less(__x._M_thread,
> __y._M_thread); }
> +#endif
> +  
> 
> What's this?

Oh, from the earlier patch attached here, which I'd forgotten about! Sorry :)