Added method on BOUND-VARIABLES specialized to FOR-AS clause.
Added method on BOUND-VARIABLES specialized to FOR-AS clause.

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