CPU functions broken in sim

[shanemadden]

possibly add alternate handling with the sim feature enabled? cpu::halt() is unavailable, and cpu::limit() and cpu::bucket() have also beed reported to be unavailable. Coalescing to 0 is likely preventing this from causing problems unless in dev mode.

[asquared31415]

I'm personally always of the opinion "if it's not meaningful, don't let the user even try", so I would disable those functions entirely on sim. I can put up a PR to do this if that's what we want.