Accelerating Y2038 glibc fixes

[Paul Eggert]

Adhemerval Zanella wrote:
> I still think that in long term this initial bump transition is better
> than to the complexity from mixed support.

Yes, that is what NetBSD did in release 6.0 (2012). OpenBSD release 5.5 (2014) 
followed suit. Admittedly these are smaller ecosystems, but the transitions went 
reasonably well as I recall. With my application-developer hat on, I prefer this 
simpler approach to the sort of complexity we went through with off_t in the 
1990s, a mess that we're still having to deal with.