[2.22] Backport malloc fixes from BZ#19048 and BZ#19243

[Florian Weimer]

On 04/12/2016 11:53 PM, Paul E. Murphy wrote:
> This attempts to backport BZ#19048, and the related fix in BZ#19243.
>
> The TLS refactoring made backporting 19048 a little more than
> trivial.  It did not raise errors after running make check for x86_64
> and ppc64le.
>
> This should get a review before pushing.

NEWS has unrelated changes.

You should also backport commits 
90c400bd4904b0240a148f0b357a5cbc36179239, 
7962541a32eff5597bc4207e781cfac8d1bb0d87, and perhaps 
2a38688932243b5b16fb12d84c7ac1138ce50363.

After that, I can compare your results with my backport for Fedora 23 
(also glibc 2.22).

Thanks,
Florian