RFR: 8292716: Configure should check that jtreg is of the required version [v3]

[Magnus Ihse Bursie]

> While reviewing the PR for [JDK-8289798](https://bugs.openjdk.org/browse/JDK-8289798) (switching to jtreg 7) I realized that it would be better if configure checked if the provided jtreg is of the minimum required version.
> 
> This PR is dependent on https://github.com/openjdk/jdk/pull/9964, so what you see here is a diff relative to that PR, and it can't be merged until that PR has been merged.

Magnus Ihse Bursie has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains three additional commits since the last revision:

 - Merge branch 'master' of https://git.openjdk.org/jdk into jtreg-version-check
 - 8292716: Configure should check that jtreg is of the required version
 - 8292717: Clean up checking of testing requirements in configure

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/9965/files
  - new: https://git.openjdk.org/jdk/pull/9965/files/e140a4e2..bb11a9c8

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=9965&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=9965&range=01-02

  Stats: 272 lines in 25 files changed: 190 ins; 47 del; 35 mod
  Patch: https://git.openjdk.org/jdk/pull/9965.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9965/head:pull/9965

PR: https://git.openjdk.org/jdk/pull/9965