RFR: 8291760: PipelineLeaksFD.java still fails: More or fewer pipes than expected [v5]

[Roger Riggs]

> Revised test to check and close all of the streams used in the pipeline.
> 
> The test now checks the content length and closes each stdout and stderr stream.
> 
> The previous technique to redirect stderr to stdout was ineffective because the fd/stream was still created in the parent process.  Created [8291986](https://bugs.openjdk.org/browse/JDK-8291986) ProcessBuilder.redirectErrorStream(true) leaves error stream available to investigate

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

  Correct loop termination to include the streams of the last Process

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/9905/files
  - new: https://git.openjdk.org/jdk/pull/9905/files/d3354444..f015a10e

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=9905&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=9905&range=03-04

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/9905.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9905/head:pull/9905

PR: https://git.openjdk.org/jdk/pull/9905