RFR: 8311291: Enable creation of NonInterleavingLogStream from LogTarget [v3]

[Johan Sjölen]

> Hi,
> 
> This patch enables the same kind of construction method for NILS that we already have for regular LogStream. We need to do some ugly changes to make it work, but it's so much more ergonomic for usage sites that I think it's worth it.

Johan Sjölen 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 four additional commits since the last revision:

 - Merge remote-tracking branch 'origin/master' into logtag
 - Move cheating out to friend classes instead
 - Adjust
 - Make NonInterLeavingLogStream less painful to use

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/14769/files
  - new: https://git.openjdk.org/jdk/pull/14769/files/86a205b5..92d4775b

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=14769&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=14769&range=01-02

  Stats: 329246 lines in 6945 files changed: 148250 ins; 113672 del; 67324 mod
  Patch: https://git.openjdk.org/jdk/pull/14769.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14769/head:pull/14769

PR: https://git.openjdk.org/jdk/pull/14769