Updates the thread dump generated by HotSpotDiagnosticMXBean.dumpThreads and jcmd Thread.dump_to_file to include thread state and lock information. Also update the HotSpotDiagnosticMXBean.dumpThreads API description to link to a description of the JSON format dump as that format is intended to be parseable/read by tools.
This PR is dependent on [pull/25425](https://github.com/openjdk/jdk/pull/25425). As noted in that PR, the changes accumulated in the loom repo, and have been split up to make it easier to review. The changes include some re-implementation of ThreadDumper. This is because it used PrintStream and didn't didn't fail if there was an I/O error, e.g. file system full. Furthermore, the indentation to pretty print the json was fragile and hard to maintain so this is changed to use a supporting writer class to do this. Test coverage is significantly expanded, including updating the test library that is used by several tests to parse the thread dump. Testing: tier1-6 ------------- Commit messages: - Initial commit - initial fix Changes: https://git.openjdk.org/jdk/pull/25429/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=25429&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8356870 Stats: 2407 lines in 16 files changed: 1985 ins; 125 del; 297 mod Patch: https://git.openjdk.org/jdk/pull/25429.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/25429/head:pull/25429 PR: https://git.openjdk.org/jdk/pull/25429
