requiredHash of a rule now includes hashes not only of SNode & SNodeRef
but also of anything except Coderules rt types (e.g. MetaLogical & DataForm).
The motivation is that if something else is used -- then it must come
from AST, so the rule must be regenerated on any changes to that data.
requiredHash is renamed to usedDataHash to reflect that fact.
In particular, fixes dependence of IndexedTupleAccess rule on idx
from `idx = tuple.index.getCompileTimeConstant()`.
6348f89d34