[PATCH][bug 48123] Install cpu_defines.h for freestanding C++ library.

[Paolo Carlini]

Hi,
> Hi,
>
>      This patch fixes the problem in bug 48123.  The problem is that
> some headers include c++config.h, which in turn includes cpu_defines.h
> but cpu_defines.h is not installed.  This has been broken for a long
> time.  Patch was tested by bootstrapping on x86_64 and building a
> cross-gcc for arm-linux-gnueabi in freestanding mode.
unless either Jakub, the release managers, or the libstdc++ maintainers 
manifest contrary opinions over the next few hours, I say Ok both 
mainline and 4_6-branch.

Paolo.