- Move code block-specific parts of code_gc.c to code_heap.c
- code_gc.c is now a generic malloc-style heap
- New code_block.c to split up large code_heap.c
- Clean up relocation code and remove some duplication
- Fix problems with code heap not being updated properly with uninterned words (bug re
ported by doublec)
- Remove boolean parameter from modify-code-heap primitive
- Less unnecessary fixup speeds up bootstrap slightly
instead of the Factor side passing the stack pointer as the first parameter, and having the VM save it to stack_chain->top, we instead have the Factor side save it. Eliminates a lot of crud in the VM