bisect-runner.pl needs to add -L/usr/local/lib prior to 5.002 on FreeBSD.

bisect-runner.pl needs to add -L/usr/local/lib prior to 5.002 on FreeBSD.

This may well also be needed on some other platforms, but as it has to be
done in the middle of the Configure run, there isn't a clean cross-platform
way to do it.

With this, FreeBSD will build all extensions back to 5.001n, and miniperl
back to 5.000. I don't think that it's going to be possible to improve on
that (without cheating and using a config.sh imported from the "future").