heap headers

[Stephen Weeks]

> On an unrelated note, does any code besides the GC ever look at the headers
> of heap objects?  I.e., suppose I went to a generational GC and I wanted
> small things ('a * 'b and 'a list where 'a and 'b require indirection) to be
> stored in older generations without the 1 word header.  Would that work or would
> some generated code get screwed up.

None of the generated code looks at headers, IIRC.  All of the code that does is 
in gc.c, I think.  The only other thing I can think of besides the gc is
saveWorld and size.