RFR: 8288984: Simplification in java.lang.Runtime::exit [v5]

[Ryan Ernst]

> This is a followup to simplify Shutdown.exit after the removal of
> finalizers (https://bugs.openjdk.org/browse/JDK-8198250). Once agreement
> on the approach has been reached in this PR, a CSR will be filed to
> propose the spec change to Runtime.exit.

Ryan Ernst 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 five additional commits since the last revision:

 - Merge branch 'master' into shutdown_cleanup
 - iter text
 - iterate on wording
 - better clarify multiple threads behavior
 - 8288984: Simplification in Shutdown.exit
   
   This is a followup to simplify Shutdown.exit after the removal of
   finalizers (https://bugs.openjdk.org/browse/JDK-8198250). Once agreement
   on the approach has been reached in this PR, a CSR will be filed to
   propose the spec change to Runtime.exit.

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/9351/files
  - new: https://git.openjdk.org/jdk/pull/9351/files/fccd85ba..75a2651e

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=9351&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=9351&range=03-04

  Stats: 2278 lines in 110 files changed: 1285 ins; 604 del; 389 mod
  Patch: https://git.openjdk.org/jdk/pull/9351.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9351/head:pull/9351

PR: https://git.openjdk.org/jdk/pull/9351