When deleting blocks in FIND-DFO, set DELETE-P first.
Made JOIN-COMPONENTS and interface so that let conversion can call it. In DFO-WALK-CALL-GRAPH, remove the function from the old component lambdas. Moved DELETE-COMPONENT-BLOCKS into ir1util, renamed it, and made it delete any redisual lambdas. Wheh finding top-level components, only consider a component top-level if the top-level lambdas is the only lambda in it. In FIND-INITIAL-DFO, only delete initial components. One of the TLL's could have been moved into a non-top-level component.