RFR: 8364361: [process] java.lang.Process should implement Closeable [v26]

[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.

Roger Riggs has updated the pull request incrementally with two additional commits since the last revision:

 - Correct reference to ProcessExamples.java to use the `file` tag.
 - Miscellaneous javadoc improvements suggested by reviewers.
   Updated the example program to be a standalone program as might be run
   as a compact source file main program.

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Changes:
  - all: https://git.openjdk.org/jdk/pull/26649/files
  - new: https://git.openjdk.org/jdk/pull/26649/files/a1bcf5ac..58176c88

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=26649&range=25
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=26649&range=24-25

  Stats: 18 lines in 2 files changed: 0 ins; 3 del; 15 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