Fix PVS build against SBCL 1.1.16 - 1.1.18+

Fix PVS build against newer versions of SBCL.  This patch comes from the Fedora
Project:
https://lists.fedoraproject.org/pipermail/scm-commits/Week-of-Mon-20140310/1204764.html
Merge pull request #35 from MJDSys/fix_sbcl

Fix PVS build against SBCL 1.1.16 - 1.1.18+