primitive support for lambda*
* libguile/memoize.c (scm_m_lambda_star): Define lambda* in the
pre-psyntax env, and make it memoize lambda* expressions.
* libguile/eval.c (BOOT_CLOSURE_PARSE_FULL): New helper.
(error_invalid_keyword, error_unrecognized_keyword): New helpers.
(prepare_boot_closure_env_for_apply): Flesh out application of boot
closures with "full" arity.
(prepare_boot_closure_env_for_eval): Punt to
prepare_boot_closure_env_for_eval for the full-arity case.
* module/ice-9/eval.scm (make-fixed-closure): Rename from `closure', and
just handle fixed arities, where there is no rest argument..
(make-general-closure): New helper, a procedure, that returns a
closure that can take rest, optional, and keyword arguments.
(eval): Adapt to call make-fixed-closure or make-general-closure as
appropriate.
* test-suite/tests/optargs.test ("lambda* inits"): Test the memoizer as
well.