[jdk11u-dev] RFR: 8272985: Reference discovery is confused about atomicity and degree of parallelism

[Goetz Lindenmaier]

I backport this for parity with 11.0.19-oracle.

One chung did not apply to referenceProcessor.cpp:836
In oop_atomic_cmpxchg() the order of arguments differs.
I adapted this also in the new code.

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Commit messages:
 - Backport fb5b144eca761d4b4c667efe05ca638536c065ac

Changes: https://git.openjdk.org/jdk11u-dev/pull/1678/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=1678&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8272985
  Stats: 82 lines in 3 files changed: 44 ins; 20 del; 18 mod
  Patch: https://git.openjdk.org/jdk11u-dev/pull/1678.diff
  Fetch: git fetch https://git.openjdk.org/jdk11u-dev pull/1678/head:pull/1678

PR: https://git.openjdk.org/jdk11u-dev/pull/1678