Add with-fresh-name-state-from-dfg

Add with-fresh-name-state-from-dfg

* module/language/cps/dfg.scm (with-fresh-name-state-from-dfg): New
  helper.
  ($dfg, compute-dfg): Store max-var and max-label in the dfg.

* module/language/cps.scm (with-fresh-name-state): Don't raise an error
  on recursive invocation; that was mostly useful when finding a bug.

* module/language/cps/arities.scm (fix-arities):
* module/language/cps/specialize-primcalls.scm (specialize-primcalls):
  Use the new helper.

* .dir-locals.el: Update.