Hi Eliot,
the VMMaker changes relative to LLP64 are so far really tiny: just the change of CCodeGenerator for >> and the memcpy.
I think it's easy enough to revert and test if it changes anything to stability.
One bad side of this kind of CCodeGenerator change is that it generates thousands of diff preventing any manual review of generated source code changes.
IMO, this should be separated in own commit so that we can bissect.
More generally, we should generate source in a more atomic fashion (for each feature/fix).
The infrastructure progress (automated tests), and the way to declare a VM stable (whatever it is) are there to enable this process.
One possibility would be to use VMMaker branches coupled to git branches like I did for LLP64.
Once we have VM smoke tests + VM simulator tests to improve confidence level, you could merge the VMMaker branch with MC, merge the necessary platforms changes with git (resolve all *src conflicts as using COG branch), regenerate the sources, and commit. I'm pretty sure that a pair of MC+git gurus could script that procedure.
If we use such process for each feature, we could integrate several features at once, with so called "octopus" merge.
This would be the process nearest to current one: the integrator (you) assemble several features for the next "release" (understand HEAD commit).
This may raise several questions about rebasing or merging changes, but it's worth thinking about it.