RFR: 8290036: Define and specify Runtime shutdown sequence [v4]

[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:

  More edits from Alex's suggestions.

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/9437/files
  - new: https://git.openjdk.org/jdk/pull/9437/files/5a16ea30..d348cca4

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=9437&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=9437&range=02-03

  Stats: 11 lines in 1 file changed: 1 ins; 2 del; 8 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