* libguile/objcodes.h:
* libguile/objcodes.c (scm_load_thunk_from_file)
  (scm_load_thunk_from_memory): New procedures.

* libguile/elf.h: Import from glibc.  Not installed.

* libguile/Makefile.am: Adapt for elf.h.

* module/system/vm/objcode.scm: (load-thunk-from-file)
  (load-thunk-from-memory): New exports.