RFR: 8291986: ProcessBuilder.redirectErrorStream(true) leaves error stream available [v2]

[Roger Riggs]

> On Linux and Mac, when a process is started, pipes are created to communicate with the child.
> In the case where the stderr is redirected to stdout using `ProcessBuilder.redirectErrorStream()`, the pipe is not needed and should not be created.
> 
> Added a test to check pipe creation when spawning with and without `redirectErrorStream(t/f)`. 
> Rewrote the extraction of pipes to use `lsof` available on Mac and Linux. (previously used Linux /proc/pid/fd/...)
> Converted PipelineLeaksFD test to JUnit.

Roger Riggs has updated the pull request incrementally with one additional commit since the last revision:

  Refactored invocation of `lsof` to not use pipes for I/O, using files instead.
  It removes the possibility of side effects that might affect the checking of pipe usage.

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Changes:
  - all: https://git.openjdk.org/jdk/pull/29143/files
  - new: https://git.openjdk.org/jdk/pull/29143/files/c8b39e4a..83d03292

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=29143&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=29143&range=00-01

  Stats: 28 lines in 1 file changed: 12 ins; 7 del; 9 mod
  Patch: https://git.openjdk.org/jdk/pull/29143.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29143/head:pull/29143

PR: https://git.openjdk.org/jdk/pull/29143