Currently we only prune recursion for createResource.
But createResource can still recurse into resourceCentric,
this can produce huge programs and may be very slow
(esp. if we already in createResource doing failing attempts).
With this change:
$ CI=yes go test -run TestMutateCorpus -count=2 ./prog
passes in ~3 seconds. If I comment out inGenerateResource
logic, it times out after 100 seconds. So this can indeed
have significant effect on generation/mutation performance.
a6d5f3ad13