RFR: 8288984: Simplification in Shutdown.exit [v2]

[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 incrementally with one additional commit since the last revision:

  better clarify multiple threads behavior

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/9351/files
  - new: https://git.openjdk.org/jdk/pull/9351/files/9d972ba6..8e7d527a

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=9351&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=9351&range=00-01

  Stats: 4 lines in 1 file changed: 1 ins; 0 del; 3 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