* gc.c (objspace_total_slot): rename objspace_available_slots.
* gc.c (objspace_live_slot, objspace_free_slot): rename
  ..._slot() to ..._slots().
* gc.c (objspace_free_slot): should subtract heap_pages_final_slots.
* gc.c (gc_stat_internal):
  * add `heap_available_slots' field
  * rename heap_live_slot to heap_live_slots
  * rename heap_free_slot to heap_free_slots
  ref: [Feature #9924]



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47488 b2dd03c8-39d4-4d8f-98ff-823fe69b080e