RFR: 8290036: Define and specify Runtime shutdown sequence [v5]

[Stuart Marks]

> Initial edits to addShutdownHook from Alex.
> 
> See [JDK-8290036](https://bugs.openjdk.org/browse/JDK-8290036).

Stuart Marks has updated the pull request incrementally with one additional commit since the last revision:

  Updates from Alan, David, and Alex.

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/9437/files
  - new: https://git.openjdk.org/jdk/pull/9437/files/d348cca4..c8b331f1

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=9437&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=9437&range=03-04

  Stats: 20 lines in 3 files changed: 0 ins; 3 del; 17 mod
  Patch: https://git.openjdk.org/jdk/pull/9437.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9437/head:pull/9437

PR: https://git.openjdk.org/jdk/pull/9437