I heard that register VMs might be slightly faster than stack VMs, and then it
occurred to me that I wouldn't know how to write a register VM if I tried. So I
wrote one (sort of).
Change-Id: I15309bca88f4b43f6e04957acedc90d9adf16673
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6902
Reviewed-by: wpcarro <wpcarro@gmail.com>
Autosubmit: wpcarro <wpcarro@gmail.com>
Tested-by: BuildkiteCI
