RFR: 8283222: improve diagnosability of runtime/8176717/TestInheritFD.java timeouts

[Daniel D.Daugherty]

While working on the following bug:

    [JDK-8282321](https://bugs.openjdk.java.net/browse/JDK-8282321) runtime/8176717/TestInheritFD.java times out during stress testing

I've made changes to the test to improve the diagnostics when test failures occur.

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Commit messages:
 - 8282321.debug

Changes: https://git.openjdk.java.net/jdk/pull/7828/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=7828&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8283222
  Stats: 188 lines in 1 file changed: 157 ins; 11 del; 20 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7828.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7828/head:pull/7828

PR: https://git.openjdk.java.net/jdk/pull/7828