a patch for "OldHeap unsed"

[satoshi kinoshita]

Hi,

system_info(procs) is currently reporting a same value for both
"OldHeap" and "OldHeap unsed".
This is a patch for erts/emulator/beam/break.c to report
"OLD_HEND(p) - OLD_HTOP(p)"
instead of
"OLD_HEND(p) - OLD_HEAP(p)"
for "OldHeap unsed".

git fetch git://github.com/kinogmt/otp.git old_heap_unused

kino