Since there are at the moment no double-valued entries, it is better to
abort early than to try to walk the zero-length array. It might even
work, but better safe than sorry.

The intention is that this release still provides the old interface
with only the new API functions as an addition. Thus, the libtool
'current' and 'age' fields are both incremented by 1.

For the RPM spec file this means that the 'so_version' macro still has
the value '8'

This is a bit cumbersome, as it involves yet another abstract
intermediate type, but necessary due to language limitations.