RFR: 8301627: System.exit and Runtime.exit debug logging [v2]

[Roger Riggs]

> It can be difficult to find the cause of calls to `java.lang.System.exit(status)` and `Runtime.exit(status)` because the Java runtime exits.
> The status value and stack trace are logged using the System Logger named `java.lang.Runtime` with message level `System.Logger.Level.DEBUG`.

Roger Riggs has updated the pull request incrementally with one additional commit since the last revision:

  Added try/catch around lookup of logger so exceptions do not prevent System.exit.
  Added test case with console logger (when java.util.logging) not present.
  Removed @implNote tag its not appropriate in implementation javadoc.
  Still looking into when and where the log configuration should be described.

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/12517/files
  - new: https://git.openjdk.org/jdk/pull/12517/files/7f149916..76c4d61f

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=12517&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=12517&range=00-01

  Stats: 26 lines in 2 files changed: 14 ins; 3 del; 9 mod
  Patch: https://git.openjdk.org/jdk/pull/12517.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12517/head:pull/12517

PR: https://git.openjdk.org/jdk/pull/12517