When C2 fails dead loop verification checks, it prints:

```
# Internal Error (/home/shipilev/shipilev-jdk/src/hotspot/share/opto/phaseX.cpp:784), pid=64465, tid=917
# assert(no_dead_loop) failed: dead loop detected
```

It also dumps the bad node graph to tty. This is not really convenient in automated testing and/or driver tests like CTW. It would be nice to print at least the node that failed verification straight into the error log.