RFR: 8364361: [process] java.lang.Process should implement close and be AutoCloseable

[Roger Riggs]

The teardown of a Process launched by `ProcessBuilder` includes the closing of streams and ensuring the termination of the process is the responsibility of the caller. The `Process.close()` method provides a clear and obvious way to ensure all the streams are closed and the process terminated.

The try-with-resources statement is frequently used to open streams and ensure they are closed on exiting the block. By implementing `AutoClosable.close()` the completeness of closing the streams and process termination can be done by try-with-resources.

The actions of the `close()` method are to close each stream and destroy the process if it has not terminated.

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Commit messages:
 - 8364361: [process] java.lang.Process should implement close and be AutoCloseable

Changes: https://git.openjdk.org/jdk/pull/26649/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=26649&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8364361
  Stats: 608 lines in 3 files changed: 604 ins; 0 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/26649.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26649/head:pull/26649

PR: https://git.openjdk.org/jdk/pull/26649