make check build failure (tst-printf-bz18872)

[Joseph Myers]

On Thu, 8 Oct 2015, Steve Ellcey wrote:

> I found one other issue while doing 'make check'.  I am using GCC 4.6.3
> on MIPS and string/tester.c didn't compile due to a
> memset-transposed-args warning.  It looks like there is handling for
> this in GCC 5.0 and later but not for 4.6.

See bug 18432.  Because this warning was backported in some vendor 
compilers we need a configure test rather than a simple version test to 
control the warning disabling (make sure the configure test is properly 
commented to explain that the option was added in GCC 5, so it's clear it 
can be removed when GCC 5 is the minimum version for building glibc).

-- 
Joseph S. Myers
joseph@codesourcery.com