[CMake] Forcing linking compatability to old libc / libstdc++ (Linux)

[Alexander Neundorf]

On 2017 M02 3, Fri 20:32:58 CET you wrote:
> FWIW, we've moved to CentOS 6 for the binaries we package and distribute
> for ParaView.  It's about the oldest widely deployed Linux distro that's
> still actively supported (EL5 is EOL'd and most deployments have long since
> moved to 6 or 7).  

Yes, most, but not all ;-)

Alex