Improve pruner, and make the AREF forms work properly in ACL where there's a subtypep bug on zero-rank array types.
Test subtypep on array types of various ranks, exhibiting a subtypep bug on rank-0 array types in ACL 6.2
Added my-with-standard-io-syntax, to get around the lack of w-s-io-s in gcl. Also, improved random-partition.
This file had been sitting around for a while. Add it to the repository now, but don't load it until there are some actual tests.