primitive-eval passes first N args on stack directly, not via apply

primitive-eval passes first N args on stack directly, not via apply

* libguile/memoize.c (MAKMEMO_CALL): Memoize in the number of arguments
  at the call site.
  (memoize, scm_m_cond, memoize_named_let, unmemoize):
* libguile/eval.c (eval): Adapt to changes in call memoization.

* module/ice-9/eval.scm (primitive-eval): For calls, pass the first N
  arguments directly on the stack, and only the rest as a consed
  argument list to apply. Currently N is 4.