The thread dump generated by HotSpotDiagnosticMXBean.dumpThreads and jcmd Thread.dump_to_file has several updates in the loom repo that should be brought to main line:

1. The implementation is changed to use a thread handshake to get a consistent snapshot of each thread.

2. The updated thread dump includes the thread state, the object if a thread is blocked on monitor enter, the parkParker if the thread is parked, the owner when the parkParker is an ownable synchronizer, and the frames where object monitors have been entered.

3. If HotSpotDiagnosticMXBean.dumpThreads throws IOException but not when writing to the file system fails. This should be fixed.

4. HotSpotDiagnosticMXBean.dumpThreads links to a JSON schema that describes the JSON format.