Use -fno-builtin for sqrt benchmark

[Tulio Magno Quites Machado Filho]

Joseph Myers <joseph@codesourcery.com> writes:

> This patch makes the sqrt benchmark use -fno-builtin, as already done
> for benchmarks of ffs and ffsll, so that it actually benchmarks the
> glibc function as (presumably) intended even in the presence of the
> compiler inlining sqrt.
>
> Tested for x86_64 and also used for benchmarking my ARM sqrt patch.
>
> 2016-10-21  Joseph Myers  <joseph@codesourcery.com>
>
> 	* benchtests/Makefile (CFLAGS-bench-sqrt.c): New variable.
>
> diff --git a/benchtests/Makefile b/benchtests/Makefile
> index 144b32e..5a61522 100644
> --- a/benchtests/Makefile
> +++ b/benchtests/Makefile
> @@ -72,6 +72,7 @@ benchset := $(string-benchset-all) $(stdlib-benchset) $(stdio-common-benchset) \
>
>  CFLAGS-bench-ffs.c += -fno-builtin
>  CFLAGS-bench-ffsll.c += -fno-builtin
> +CFLAGS-bench-sqrt.c += -fno-builtin
>
>  bench-malloc := malloc-thread

LGTM.

-- 
Tulio Magno