[jdk17u] RFR: 8214761: Bug in parallel Kahan summation implementation

[Joe Darcy]

8214761: Bug in parallel Kahan summation implementation

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Commit messages:
 - Backport dd871819a05886ee09fc00c7c778268440ebedb7

Changes: https://git.openjdk.java.net/jdk17u/pull/81/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk17u&pr=81&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8214761
  Stats: 235 lines in 5 files changed: 225 ins; 0 del; 10 mod
  Patch: https://git.openjdk.java.net/jdk17u/pull/81.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk17u pull/81/head:pull/81

PR: https://git.openjdk.java.net/jdk17u/pull/81