Make programs.h private

This header file turns out to only have internal details.  Users that
need introspection can use Scheme.

* libguile/programs.h (SCM_PROGRAM_P, SCM_PROGRAM_CODE)
(SCM_PROGRAM_FREE_VARIABLES, SCM_PROGRAM_FREE_VARIABLE_REF)
(SCM_PROGRAM_FREE_VARIABLE_SET, SCM_PROGRAM_NUM_FREE_VARIABLES)
(SCM_VALIDATE_PROGRAM, SCM_F_PROGRAM_IS_BOOT, SCM_F_PROGRAM_IS_PRIMITIVE)
(SCM_F_PROGRAM_IS_PRIMITIVE_GENERIC, SCM_F_PROGRAM_IS_CONTINUATION)
(SCM_F_PROGRAM_IS_PARTIAL_CONTINUATION, SCM_F_PROGRAM_IS_FOREIGN)
(SCM_PROGRAM_IS_BOOT, SCM_PROGRAM_IS_PRIMITIVE)
(SCM_PROGRAM_IS_PRIMITIVE_GENERIC, SCM_PROGRAM_IS_CONTINUATION)
(SCM_PROGRAM_IS_PARTIAL_CONTINUATION, SCM_PROGRAM_IS_FOREIGN): Remove
these macros, as we are making this whole API private.
(struct scm_program, scm_is_program, scm_to_program, scm_from_program)
(scm_program_flags, scm_program_is_boot, scm_program_is_primitive)
(scm_program_is_primitive_generic, scm_program_is_continuation)
(scm_program_is_partial_continuation, scm_program_is_foreign)
(scm_program_code, scm_program_free_variable_count)
(scm_program_free_variable_ref, scm_program_free_variable_set_x)
(scm_i_make_program): New inline functions.
* libguile/Makefile.am (noinst_HEADERS): Add programs.h; no longer
installed.  It was never directly included from libguile.h.
* libguile/continuations.c:
* libguile/continuations.h:
* libguile/control.c:
* libguile/foreign.c:
* libguile/frames.c:
* libguile/frames.h:
* libguile/goops.c:
* libguile/gsubr.c:
* libguile/gsubr.h:
* libguile/intrinsics.h:
* libguile/procprop.c:
* libguile/procs.c:
* libguile/programs.c:
* libguile/stacks.c:
* libguile/vm-engine.c:
* libguile/vm.c:
* libguile/vm.h: Adapt all users.

libguile/frames.c

@@ -33,6 +33,7 @@
 #include "numbers.h"
 #include "pairs.h"
 #include "ports.h"
+#include "programs.h"
 #include "symbols.h"
 #include "threads.h"
 #include "variable.h"