GovernorMockEnvironment shrinker bug

[crocodile-dentist]

Something apparently causes an infinite loop somewhere as after over a 1,000 shrinks I've aborted a failed tests.

[crocodile-dentist]

There doesn't seem to be a non-termination bug in any of the shrinkers, and what causes the long shrink is shrinking the targets. I think these should not be shrunk independently, but together with related things.