Limit regression with 5.17.1/clisp 2.46



Hello folks,

I have seen the following regressions with 5.17.1 and clisp 2.46 (even 
though I doubt the lisp version is relevant)

In 5.16.3:

(%i1) limit(1/x,x,0);
(%o1)                                 und


In 5.17.1:

(%i1) limit(1/x,x,0);
(%o1)                              infinity

I ran Sage's test suite and there are other issues - for example 
simplification when erf is involved, but I will sort through those and 
boil them down to simple examples.

Cheers,

Michael