Fast generic function dispatch without calling `compile' at runtime

Fast generic function dispatch without calling `compile' at runtime

* module/oop/goops.scm: Rewrite generic function dispatch to use chained
  closures instead of compiling specific dispatch procedures.  The big
  speed win before was not allocating rest arguments, which we gain by
  simply pre-generating dispatchers for arities of up to 20 arguments.
  Also now a tail call without reshuffling arguments -- which is what
  dispatch now is -- is just a (mov 0 new-procedure) and (tail-call),
  which is pretty cheap.

  (%invalidate-method-cache!): Use the new
  recompute-generic-function-dispatch-procedure!.
  (arity-case, multiple-arity-dispatcher, single-arity-dispatcher)
  (single-arity-cache-dispatch)
  (compute-generic-function-dispatch-procedure)
  (recompute-generic-function-dispatch-procedure!): New internal
  interfaces.
  (memoize-effective-method!): Update for new interfaces.
  (memoize-generic-function-application!): Rename from `memoize-method!'.