RFR: 8323791: Parallel: Using non-atomic for live bytes update during Full GC [v4]

[Albert Mingkun Yang]

> Simple optimization to avoid atomic-operation during Full GC marking.
> 
> Test: Full GC pause length shows ~1% regresion when using single gc-thread and ~20% improvement when using multiple gc-threads using the attached program.

Albert Mingkun Yang has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains one additional commit since the last revision:

  pgc-fullgc-livebyte

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Changes:
  - all: https://git.openjdk.org/jdk/pull/17442/files
  - new: https://git.openjdk.org/jdk/pull/17442/files/c8ea2739..4a423b4f

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=17442&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=17442&range=02-03

  Stats: 4061 lines in 214 files changed: 2668 ins; 818 del; 575 mod
  Patch: https://git.openjdk.org/jdk/pull/17442.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17442/head:pull/17442

PR: https://git.openjdk.org/jdk/pull/17442