space profiling

[Henry Cejtin]

I  just  realized that the space profiling is definitely going to have a real
problem with overflowing the bins.  If I have a hot loop allocating  lots  of
junk,  it  isn't  hard  for one location to be responsible for more than 2^32
bytes of allocation.  This seems like another  argument  for  going  for  the
procedure call, and having the linked list use 64 bits worth of counter (plus
32 bits for the link).  This way you are safe from wrapping.