[patch] update zlib to the 1.2.10 release.

[Nick Clifton]

Hi Joel,

> Can you tell us what these changes are? Currently nightly source
> packaging is broken while configuring zlib.

>     ./config.status: line 1191: ./../../config-ml.in: No such file or directory
>     Makefile:10001: recipe for target 'configure-zlib' failed

I have checked in a patch to restore the old behaviour to zlib's Makefile
and allow building with srcdir == builddir.  At least for now.  If we do 
decide to ban this behaviour then this patch can be reverted, or a top level
check and warning added.

Cheers
  Nick

zlib/ChangeLog.bin-gdb
2017-01-23  Nick Clifton  <nickc@redhat.com>

	* configure.ac: Restore old behaviour of only enabling multilibs
	when a target subdirectory is defined.  This allows building with
	srcdir == builddir.
	* configure: Regenerate.