Backport from trune:

[Jakub Jelinek]

On Mon, Aug 12, 2013 at 01:01:46PM +0100, Andrew Haley wrote:
> I think this one is obvious/trivial, but I'll ask anyway.
> 
> OK?

To 4.8?  Sure.

> 2013-08-12  Andrew Haley  <aph@redhat.com>
> 
> 	Backport from mainline:
> 	* 2013-07-11  Andreas Schwab  <schwab@suse.de>
> 
> 	* config/aarch64/aarch64-linux.h (CPP_SPEC): Define.
> 
> Index: gcc/config/aarch64/aarch64-linux.h
> ===================================================================
> --- gcc/config/aarch64/aarch64-linux.h	(revision 201661)
> +++ gcc/config/aarch64/aarch64-linux.h	(working copy)
> @@ -23,6 +23,8 @@
> 
>  #define GLIBC_DYNAMIC_LINKER "/lib/ld-linux-aarch64.so.1"
> 
> +#define CPP_SPEC "%{pthread:-D_REENTRANT}"
> +
>  #define LINUX_TARGET_LINK_SPEC  "%{h*}		\
>     %{static:-Bstatic}				\
>     %{shared:-shared}				\

	Jakub