RFR: 8302189: Mark assertion failures noreturn

[Kim Barrett]

Also 8302799: Refactor Debugging variable usage for noreturn crash reporting

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

Commit messages:
 - new implementation of Debugging
 - noreturn attributes

Changes: https://git.openjdk.org/jdk/pull/12845/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=12845&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8302189
  Stats: 168 lines in 8 files changed: 128 ins; 19 del; 21 mod
  Patch: https://git.openjdk.org/jdk/pull/12845.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12845/head:pull/12845

PR: https://git.openjdk.org/jdk/pull/12845