variable was defined, but had an empty value (reported by Peter Van Eynde)
* bug fix: non ordinary lambda-list keyword in ordinary lambda lists
signal a PROGRAM-ERROR, not a BUG.
+ * bug fix: SB-POSIX:READDIR works when built with large file support.
* optimization: loading generic functions no longer takes O(n^2) time,
proportional to the amount of methods in the generic function
(reported by Todd Sabin and Jeremy Brown)