RFR: 8291986: ProcessBuilder.redirectErrorStream(true) leaves error stream available [v3]

[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 two additional commits since the last revision:

 - Some test platforms do not have `lsof` installed, if not available,
   the tests are skipped.
 - Remove extra -Xint test run, its purpose is unknown.

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/29143/files
  - new: https://git.openjdk.org/jdk/pull/29143/files/83d03292..38328d56

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=29143&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=29143&range=01-02

  Stats: 29 lines in 1 file changed: 21 ins; 8 del; 0 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