- declared input type for bignum-shift was stricter than the runtime behavior, leading to bad propagation of type info if shift count was a bignum
- types inferred for type functions which used number-valued/integer-valued/real-valued were not always precise, eg bignum bignum bitxor => integer
- add interval-log2, type function for (log2)
- remove math-class-min, it was useless
Non-optimizing compiler now special-cases dip, 2dip, 3dip following a
literal quotation: this allows us to break the dip/slip meta-circle
without explicit calls to >r/r>