C++ PATCH: PR 20599 (1/3)

[Benjamin Kosnik]

> So, with that amendment, i.e., with the addition of:
> 
> (d) predefine a macro (or macros) that indicates that we're in C++0x mode
> 
> are there objections to the policy set out above?  Point (d) doesn't 
> mean that we can't predefine many macros (for various features) or that 
> we have to use any particular value; it's just saying that we'll give 
> users some way of figuring out what dialect of C++ they're using.

Looks good to me. Gaby is right about issues with __cplusplus and "C"
includes on some platforms (notably solaris), so solutions based on
this key are not very appealing.

-benjamin