static opcodes; refactor program/objcode division; use new assembly pipeline

static opcodes; refactor program/objcode division; use new assembly pipeline

* gdbinit: Untested attempts to get the stack fondling macros to deal
  with the new program representation.

* libguile/frames.c (scm_vm_frame_arguments, scm_vm_frame_source)
  (scm_vm_frame_local_ref, scm_vm_frame_local_set_x): SCM_PROGRAM_DATA is
  a struct scm_objcode*.

* libguile/instructions.h:
* libguile/instructions.c: Hide the instruction table and the struct
  scm_instruction structure; all access to instructions now goes through
  procedures. This is because instructions are no longer in a packed
  array indexed by opcode. Also, declare a mask that all instructions
  should fit in.

* libguile/objcodes.h:
* libguile/objcodes.c: Rewrite so that object code directly maps its
  arity and length from its bytecode. This makes it unnecessary to keep
  this information in programs, allowing programs to be simple conses
  between the code (objcodes) and data (the object table and the closure
  variables).

* libguile/programs.c (scm_make_program): Rework so that make-program
  takes objcode, an object table, and externals as arguments. It's much
  clearer this way, and we avoid malloc().

* libguile/stacks.c (is_vm_bootstrap_frame): Update for program/objcode
  changes.

* libguile/vm-engine.c (vm_run): Initialize the jump table on the first
  run, with the opcodes declared in the instruction sources, and with bad
  instructions raising an error instead of wandering off into the
  Unknown.

* libguile/vm-engine.h (FETCH_LENGTH): Always represent lengths as 3
  bytes. The old code was too error-prone.
  (NEXT_JUMP): Mask the instruction with SCM_VM_INSTRUCTION_MASK.
  (NEW_FRAME): Update for program/objcode changes.

* libguile/vm-expand.h (VM_DEFINE_FUNCTION, VM_DEFINE_INSTRUCTION)
  (VM_DEFINE_LOADER): Update so that we explicitly specify opcodes, so
  that we have a stable bytecode API.

* libguile/vm-i-loader.c: Update license to LGPLv2+. Explicitly declare
  opcodes.
  (load-integer): Use an int instead of a long as the accumulator; still
  need to revisit this code at some point, I think.
  (load-program): Simplify, thankfully!! Just creates the objcode slice
  and rolls with it.

* libguile/vm-i-scheme.c: Number the opcodes explicitly.

* libguile/vm-i-system.c: Update license to LGPLv2+. Explicitly declare
  opcodes.
  (make-closure): Update for new program API.

* libguile/vm.c (vm_make_boot_program): Update for new program/objcode
  API. Still a bit ugly.
  (scm_load_compiled_with_vm): Update for new program/objcode API.

* module/language/assembly.scm (byte-length): Fix byte-length calculation
  for loaders, and load-program.
  (code-pack, code-unpack): Start to move things from (system vm conv)
  here.
  (object->code, code->object): More things from conv.scm.

* module/language/glil.scm (<glil-program>): Add a new field,
  closure-level.
  (make-glil-program, compute-closure-level): Calculate the "closure
  level" when making a glil program. This is the maximum depth of
  external binding refs in this closure.
  (unparse-glil): Fix label serialization.

* module/language/glil/compile-assembly.scm (make-meta): Prepend #f for
  the meta's object table, though maybe in the future we can avoid
  creating assembly in the first place.
  (assoc-ref-or-acons, object-index-and-alist): GRRR! Caught again by the
  different sets of arguments to assoc and assoc-ref!
  (glil->assembly): Attempt to make the <glil-program> case more
  readable, and fix the bugs. Sorry I don't know how to comment this
  change any more than this.
  (glil->assembly): For <glil-module> serialize the whole key, not just
  the name.
  (dump-object): subprogram-code is already a list. Serialize integers as
  strings, not u8vectors. Fix the order of lists and vectors.

* module/language/glil/spec.scm (glil): Switch orders, so we prefer glil
  -> assembly -> objcode. Actually glil->objcode doesn't work any more,
  needs to be removed I think.

* module/language/objcode/spec.scm (objcode->value):
  s/objcode->program/make-program/.

* module/language/scheme/inline.scm: Add acons inline.

* module/system/vm/conv.scm (make-byte-decoder): Skip the first 8 bytes,
  they are header. Handle subprograms properly. Still needs help though.
  (decode-length): Lengths are always 3 bytes now.

* module/system/vm/disasm.scm: Superficial changes to keep things
  working. I'd like to fix this better in the future.

* module/system/vm/frame.scm (bootstrap-frame?): Fixes for
  program-bytecode.

* module/system/vm/program.scm: Export make-program. It's program-objcode
  now, no more program-bytecode.

* module/system/vm/vm.scm (vm-load): Use make-program.

* test-suite/tests/asm-to-bytecode.test: New test, very minimal.

* module/system/vm/objcode.scm: Export word-size, byte-order, and
  write-objcode.