[PATCH] malloc: Deprecate hook variables, __default_morecore, <mcheck.h>

[Florian Weimer]

I still feel we have a fairly complete set of replacements available 
today (Address Sanitizer, valgrind for debugging; interposition instead 
of __more_core &c), and that it makes sense to announce our planned 
deprecation early.

It does, however, look rather unlikely I will have concrete to show by 
the end of December 2016.

Final comments?

Thanks,
Florian