This allows dagger.io/dagger/op.#Op to be maintained in regular
uncommented CUE, but not participate by default in normal dagger
evaluation (given the performance problems it currently introduces).
The "full" #Op can be enabled by passing the "-t fullop" flag:
cue eval -t fullop ./examples/react
(which currently triggers the performance issue).
Signed-off-by: Paul Jolly <paul@myitcv.io>
