RFR: 8302496: Runtime.exit incorrectly says it never throws an exception

[Stuart Marks]

Textual specification clarifications.

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Commit messages:
 - 8302496: Runtime.exit incorrectly says it never throws an exception

Changes: https://git.openjdk.org/jdk/pull/13706/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=13706&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8302496
  Stats: 29 lines in 2 files changed: 5 ins; 2 del; 22 mod
  Patch: https://git.openjdk.org/jdk/pull/13706.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13706/head:pull/13706

PR: https://git.openjdk.org/jdk/pull/13706