fix procedure naming

fix procedure naming

* module/ice-9/psyntax.scm (define-expansion-accessors): New helper, to
  define accesors for a particular expansion data structure. Use it
  later to define lambda?, lambda-meta, and set-lambda-meta!.
  (maybe-name-value): Update to work with the newly defined accessors.
  (build-global-reference, build-let, build-named-let, build-letrec):
  Re-enable naming of procedures.

* module/ice-9/psyntax-pp.scm: Regenerated.