separate assembly

[Matthew Fluet]

> > Thus
> > you  are pretty much forced to do some kind of intelligent splitting (perhaps
> > at a top-level function boundary).
> 
> I agree with Henry.  I think the right way to split is to partition the toplevel 
> functions into disjoint sets, with one set per assembly file.  A new chunkifier
> that does that should be trivial.

Sounds reasonable.  Can we leverage the existing chunkifier to get us
partially there?  My first thought would be to use the existing chunkifier
with ChunkPerFunc which would give us a minimum granularity.  I haven't
looked at too many programs, but I would think that one assembly file per
func is too many.  So, probably do some sort of quick bin-packing of
chunks into super-chunks with approximately the right number of statements
per assembly file.