Otherwise the expression denotations are unsound between the 2 phases

Time travel does not work after LambdaLift
because LambdaLift creates new symbols.
To resolve a term by reflection we need to know its name
after BGen, and its capture. So we insert a phase after all
the transform phases, called resolve-reflect-eval whose
purpose is to resolve the temporary reflectEval calls into
more precise methods. The EvaluationStrategy
attachment conveys information about the term that
must be evaluated.