8229496: SIGFPE (division by zero) in C2 OSR compiled method Summary: Adding a CastNode to keep the dependency between the div/mod operation and the zero check. Reviewed-by: roland, mdoerr

8177068: incomplete classpath causes NPE in Flow Summary: Undo completions that failed during speculative attribution, so that the appropriate CompletionFailures are thrown again and properly reported. Reviewed-by: vromero