Astshim build on OpenSuse

Thought this might be useful for OpenSuse or similar Linux flavor users.

If astshim fails (cannot find .so shared libraries), a link should be made manually under
Linux64/starlink_ast/[version]
ln -sf lib64 lib

This is somewhat related to:
https://jira.lsstcorp.org/browse/DM-326

I think the answer is to fix starlink_ast eupspkg.cfg.sh the same way we fixed it for GSL. That is, add --libdir explicitly. @rowen I think that will work since it’s all autoconf.

Implemented as https://jira.lsstcorp.org/browse/DM-10996