[PATCH] Update C++17 library implementation status table

[Jonathan Wakely]

On 04/08/16 14:32 +0100, Jonathan Wakely wrote:
>This adds all the features from the latest draft of SD-6, and
>reformats the table to be closer to the tables at
>https://gcc.gnu.org/projects/cxx-status.html (including adding the
>feature-test macros).

I'd like to do the same for the C++14 status table (since SD-6 also
defines macros for C++14 features). If somebody else wants to do that
work, including figuring out which release added each component, I
would be very grateful. Otherwise I'll do it in a couple of weeks.