[v3, C++] RFC: PATCH to add decimal floating point typeinfos to libsupc++

[Paolo Carlini]

Hi, Jason
> Because I don't know about such things.  :)
> I'll try that instead of the baseline change.
Ok ;) Anyway, what I'm suggesting is the standard way of dealing with
such things. In general, baseline changes are *very* uncommon, it should
be set in stone, representing the 3.4.0 ABI, to which we are only adding.
> The Makefile changes aren't really part of this change, just some
> brokenness I noticed when I tried to do 'make new-abi-baseline' to
> update the baseline.
Agreed.

Paolo.