RFR: 8297657: name demangling intermittently fails [v2]

[Fredrik Bredberg]

> Fixes an intermittent name demangling problem (due to the uninitialized AbstractDecoder::_decoder_status field).
> The problem affected hs-err stack traces on macosx-aarch64 and macosx-amd64.
> 
> I've done manual testing to verify the problem and the solution.
> Also run tier1-5 after the fix without seeing any new problems.

Fredrik Bredberg has updated the pull request incrementally with one additional commit since the last revision:

  Updated after review

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/13883/files
  - new: https://git.openjdk.org/jdk/pull/13883/files/3605d84f..890046bf

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=13883&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=13883&range=00-01

  Stats: 16 lines in 4 files changed: 2 ins; 8 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/13883.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13883/head:pull/13883

PR: https://git.openjdk.org/jdk/pull/13883