bug#23760: 25.0.95; emacs 25.0.95 doesn't build with glibc-2.23.90

[Paul Eggert]

On 06/20/2016 10:48 AM, Florian Weimer wrote:
> > aren't we better off having glibc simply not declare
> > __malloc_initialize_hook?
>
> You mean, not declare it in <malloc.h>?

Yes, that's what I meant.

> I'm more worried about the other __ variables in the Emacs malloc. 
> Their in Emacs definition does not even match the one in glibc. The 
> difference is probably harmless, but it is fairly close to be being 
> broken.

The intent is that __malloc_initialize_hook and the other __ variables 
will become inoperative in glibc, right? That is, glibc won't set or use 
or care about these obsolete variables. If so, we should be OK with 
Emacs master as-is: when it substitutes its own (even-more-obsolescent) 
malloc it will set and use these variables freely, and this won't 
collide with any glibc use.