[COMMITTED] Fix GCC6 build errors due to unused statics

[Joseph Myers]

On Fri, 18 Sep 2015, Wilco Dijkstra wrote:

>     2015-09-18  Wilco Dijkstra  <wdijkstr@arm.com>
>     
>             * timezone/Makefile: Ignore unused variable errors due to private.h
>             (time_t_min) and (time_t_max).

I've reverted this timezone/Makefile change since it broke the build for 
all released versions of GCC, which is more important than the build with 
GCC 6 (where we have several months before a release to work out what 
warnings should be there at all).

Please recalibrate your notion of obviousness so you are much more wary of 
committing patches that haven't been reviewed.  See the list of obvious 
types of changes at <https://sourceware.org/glibc/wiki/Consensus>.

Someone indicating a general direction without having seen a patch is 
*not* approval for some arbitrary future patch following that direction, 
unless they specifically say e.g. "OK with that change".

-- 
Joseph S. Myers
joseph@codesourcery.com