the current reason for the crash is that a branch object which is
on the branch with the token of 268 and a location of c804e0 has
not been migrated to a new page when the page was collected.

the object which points to the lost object earlier is at 989cb0.
and is properly listed in the pointer ref set on that page.  you 
can see it in the third word over when using x/4 0xc80050

you can see the crash faster, and the daage even faster by
runing with recycleOld off.  it takes 209 hits of gc and
97 hits at 1239 to get to the point where the pointer to the
in the pointer ref set gets forgotten.  it takes to 147 hits on 
the gc for the problem to cause a crash.
