RFR: 7903848: JCStress: Use "out" field consistently [v2]

[Johnny Lim]

> This PR changes to use `out` field consistently in the `JCStress` as it would be better for internal consistency although it's effectively same as before.

Johnny Lim 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 two additional commits since the last revision:

 - Merge branch 'master' into polish-JCStress
 - Use "out" field consistently in JCStress

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

Changes:
  - all: https://git.openjdk.org/jcstress/pull/151/files
  - new: https://git.openjdk.org/jcstress/pull/151/files/3e54942b..403cc88e

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jcstress&pr=151&range=01
 - incr: https://webrevs.openjdk.org/?repo=jcstress&pr=151&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jcstress/pull/151.diff
  Fetch: git fetch https://git.openjdk.org/jcstress.git pull/151/head:pull/151

PR: https://git.openjdk.org/jcstress/pull/151