libstdc++ support for --enable-version-specific-runtime-libs

[markh@frazier.landmark.com]

libstdc++ Maintainers,

   It appears that support for installing libstdc++ libraries in the
   compiler's version-specific directories (i.e., 2.95, 2.95.2, etc.)
   has been removed from configure.in/Makefile.in for
   libstdc++-2.90.8.  Was this done intentionally, or are there plans
   to restore support for this configuration switch?  The switch is
   relatively important because the gcc/g++ compiler changes fairly
   frequently, and so it is necessary to have multiple versions of the
   compiler installed, with corresponding versions of the libraries.
   Or have I misunderstood something about the
   configuration/installation of libstdc++?

-- 
## Mark Harig
## Landmark Systems, Reston, Virginia, USA
## Email: mharig@landmark.com