TMI: Everything is broken

Today featured: the mystery of the overlapping node IDs -- which was causing yesterday's unsolved problem. Due to my get-around-the-borrow-checker hack, I was copying the session in a way that didn't actually copy all the state. So I was resetting the unique-ID counter to zero after doing the initial parsing, expansion, and injection of various primitives. This caused the obvious problems. Once I fixed that, I ran into the driver... not generating output when I called it from rustpkg on a library. That's bad. Haven't figured out why yet.

Unrelatedly, I've been trying to bisect a performance regression that I noticed in the compiler, though I'm not sure anyone else is seeing it (others have commented on a memory regression, but I'm noticing a time regression too). The first round of bisecting pointed to the commit from 5 days ago that updated the snapshot. So that suggests a performance problem that had been in stage2 and then snuck into stage1 when the snapshot got updated. So now I'm doing a second round of bisecting to figure out when the stage2 problem showed up, which is much slower.

And when both of those things are compiling, fixing warnings, which is almost done.