[move-only] Ensure that if we have an allocation that isn't fully initialized (and DI errors on it as such), the move checkers do not run on the allocation.
Previously we would crash.
Since we are relatively late in 5.9, my solution is to just turn off the move
checker on functions whenever DI would emit an error. If we were earlier in the
development cycle, then I would make the error be a per allocation change.
rdar://108993297