[hurd,commited 2/2] x86 tls: Use _Static_assert for TLS access size assertion

[Florian Weimer]

* Samuel Thibault:

> ---
>  sysdeps/i386/nptl/tls.h      | 46 ++++++++++++++++--------------------
>  sysdeps/mach/hurd/i386/tls.h | 46 ++++++++++++++++--------------------
>  sysdeps/x86_64/nptl/tls.h    | 46 ++++++++++++++++--------------------
>  3 files changed, 60 insertions(+), 78 deletions(-)
>
> diff --git a/sysdeps/i386/nptl/tls.h b/sysdeps/i386/nptl/tls.h
> index ffead90857..28053a77f3 100644
> --- a/sysdeps/i386/nptl/tls.h
> +++ b/sysdeps/i386/nptl/tls.h
> @@ -255,6 +255,9 @@ tls_fill_user_desc (union user_desc_init *desc,
>  /* Read member of the thread descriptor directly.  */
>  # define THREAD_GETMEM(descr, member) \
>    ({ __typeof (descr->member) __value;					      \
> +     _Static_assert (sizeof (__value) == 1				      \
> +		  || sizeof (__value) == 4				      \
> +		  || sizeof (__value) == 8);				      \
>       if (sizeof (__value) == 1)						      \

This (and the other changes) broke the x86_64-linux-gnu build.  I'm
testing a fix.