separately compiling libc modules for rtld

[Roland McGrath]

> I'd rather prefer to wait for 2.3.1.  This looks like a patch which can
> have many hidden possibilites to break something.

Indeed so.  

> I know that Hurd has problems.  But exported symbols temporarily should
> be able to fix that, right?  And it also doesn't introduce any permanent
> ABI damage.  So I'd rather go this way unless you prefer to not change
> the code and declare 2.3.1 as the first release usable for Hurd.

That would be ok with me, but it might be hard for the Debian/Hurd guys.

There is never any question of ABI breakage that I know of, just that it
works or it doesn't or it has too many PLT entries and is less optimal.  
It seems to me the simplest thing for now would be to make it easy to just
disable all the hidden_proto stuff entirely and have Hurd do that.  
I'll add something.