prompt as part of guile's primitive language

prompt as part of guile's primitive language

* libguile/control.h:
* libguile/control.c: Remove scm_atcontrol and scm_atprompt.
  (scm_c_make_prompt): Remove handler arg, as the handler is inline.
  (scm_abort): New primitive, exported to Scheme as `abort'. The
  compiler will also recognize calls to `abort', but this is the base
  case.
  (scm_init_control): Remove scm_register_control, just have this
  function, which adds `abort' to the `(guile)' module.

* libguile/eval.c (eval): Add SCM_M_PROMPT case.

* libguile/init.c (scm_i_init_guile): Change scm_register_control call
  into a nice orderly scm_init_control call.

* libguile/memoize.h: (scm_sym_at_prompt, SCM_M_PROMPT):
* libguile/memoize.c (MAKMEMO_PROMPT, scm_m_at_prompt, unmemoize): Add
  prompt support to the memoizer.

* libguile/vm-i-system.c (prompt): Fix to not expect a handler on the
  stack.

* module/ice-9/boot-9.scm (prompt): Add definition in terms of @prompt.

* module/ice-9/control.scm: Simplify, and don't play with the compiler
  here, now that prompt and abort are primitive.

* module/ice-9/eval.scm (primitive-eval): Add a prompt case.

* module/language/tree-il/primitives.scm
  (*interesting-primitive-names*): Add @prompt and prompt.