Thu Jun 12 12:19:39 CEST 2008

compiler state operations

These need to be factored out a bit.

I do need to be careful about providing primitives that are
non-destructive, and leave destruction to simple destructors.

org-pop is:   terminate-chain

I'm going to leave this as is until I need a different mechanism that
needs to split/merge the compiler state.

AHA: split and merge.

pop-chain =  terminate-chain
             combine-chains    ;; only for org

push-chain = split-state

split-state: save current asm, rs and dict on the control stack, and
             start with a clean slate.

merge-state: merge current asm, rs and dict with the one on the
             control stack.