libstdc++ PATCH to use __cplusplus rather than __GXX_EXPERIMENTAL_CXX0X__

[Ed Smith-Rowland]

On 11/09/2012 05:09 PM, Jason Merrill wrote:
> Now that G++ uses the value of __cplusplus specified by the standard, 
> we don't need the other macro anymore.
>
> OK for trunk, or should I save it for the next stage 1?
>
> Jason
This looks like a non-user-facing mechanical change that makes sense.  
FWIW I'm OK with it.

Paolo?

Ed