Factor/To do/GC

• weak pointers
• weak hashtables
• finalizers
• incremental gc
• Distant future: parallel GC, concurrent GC

If we go with immix, here's the plan:

• Implement mark-sweep(-compact), which will be used for the large object space (necessary since immix can't handle large objects)
• Implement a mark-region collector without evacuation or lines for small objects
• Implement evacuation
• Implement lines

done

• promote objects to tenured after a certain number of collections (or in some other way improve generational strategy because aging space thrashes)
• id-hashcode
• mark/sweep for oldest generation--what kind of compaction should be used?
• - plain old mark-compact
• - the compressor
• - mark-copy
• - Immix
• Card marking for parts of arrays
• card marking for code heap to speed up collect_literals