We recently relaxed some of the limits for big FSTs, but there is
one more limit I think we should fix. E.g. Aaron hit it in building
the world's biggest FST: http://aaron.blog.archive.org/2013/05/29/worlds-biggest-fst/
The issue is NodeHash, which currently uses a GrowableWriter (packed
ints impl that can grow both number of bits and number of values):
it's indexed by int not long.
This is a hash table that's used to share suffixes, so we need random
get/put on a long index of long values, i.e. this is logically a long.
I think one simple way to do this is to make a "paged"
Along with this we'd need to fix the hash codes to be long not