This reverts commit ac70b37a00dc02bd8923e0a4602d26be4581c570
which reverted commit 8aeb2fe13a4100b4c2e78d6ef75119304100cb1f
because codegen tests got broken and i needed time to investigate.
This shows some regressions in tests, but they are all around GEP's,
so i'm not really sure how important those are.
https://rise4fun.com/Alive/1Gn