jdk-9-ea+105 breaks MinimizeOperations.minimize()

As soon as jdk-9-ea+105 was put into test rotation, automaton tests have been sporatically failing in non-reproducible ways. All of them invoke hopcroft minimization either directly or indirectly.

The bug manifests in several forms:

• ArrayIndexOutOfBoundsException in minimize()
• IllegalArgumentException for an explicit bounds check
• incorrect resulting automaton

This method is ... let's say not the ideal one to debug something like this, but I've at least got it where I can make it fail in a few minutes with beasting, so we can try simple things like turning on/off jvm flags to try to narrow it more.

It would be really great to make it fail more efficiently, but unfortunately it takes many thousands of iterations until we understand more about it.