deprecated sunrpc and rpc/netdb.h

[Roland McGrath]

> When it's a full replacement, we should also work out how to stop as much 
> as possible of the deprecated code from being built at all for future 
> architecture ports (so that for ports whose lowest symbol version is 
> GLIBC_2.24 or whatever, the symbols don't exist in the glibc ABI even as 
> compat symbols and --enable-obsolete-rpc isn't allowed at all).

Heartily agreed!  I started to take a stab at this quite a while ago, but
gave up quickly.  I think it will be substantially simpler if we've first
gotten all YP/NIS/NIS+-related code out of libc entirely (when TI-RPC or
another project depending on it supplies libnss_{nis,nisplus,compat} and
libnsl so no libc configuration needs to do so even for ABI compatibility).


Thanks,
Roland