Multiple relations for the CONDITION-REPORT node kind.

[robert-strandh]

The node kind :CONDITION-REPORT takes a single argument which is either a symbol,
a string, or a lambda expression. But three different relations are used, namely :FUNCTION,
:LAMBDA and :STRING. It seems to me that the different cases can be distinguished by
the KIND of the node being related to, so that a single relation can be used in this case.