Coming now: jtreg 7.3.1

[Christian Stein]

JDK folk,

This is a general heads-up that jtreg 7.3.1 is ready for use and
that we are updating JDK to use it. This release fixes a regression
introduced in jtreg 7.3 that prevented to set up default
environment variables correctly on Windows.

Find a listing of noteworthy changes at [1].

Thanks to everyone who has helped finding and fixing this bug.

[1] https://github.com/openjdk/jtreg/blob/master/CHANGELOG.md