Added another test for FOR-THE-HASH-KEYS-OF with NIL variable.
Added another test for FOR-THE-HASH-KEYS-OF with NIL variable.

clasp-developers/SICL,clasp-developers/SICL,vtomole/SICL,vtomole/SICL,clasp-developers/SICL,vtomole/SICL,clasp-developers/SICL,vtomole/SICL