RFR: 8335902: Parallel: Refactor VM_ParallelGCFailedAllocation and VM_ParallelGCSystemGC [v4]

[Albert Mingkun Yang]

> Similar cleanup as https://github.com/openjdk/jdk/pull/19056 but in Parallel. As a result, the corresponding code in `SerialHeap` and `ParallelScavengeHeap` share much similarity.
> 
> The easiest way to review is to start from these two VM operations, `VM_ParallelCollectForAllocation` and `VM_ParallelGCCollect` and follow the new code directly, where one can see how allocation-failure triggers various GCs with different collection efforts.
> 
> Test: tier1-6; perf-neural for dacapo, specjvm2008, specjbb2015 and cachestresser.

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 five additional commits since the last revision:

 - Merge branch 'master' into pgc-vm-operation
 - review
 - review
 - Merge branch 'master' into pgc-vm-operation
 - pgc-vm-operation

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/20077/files
  - new: https://git.openjdk.org/jdk/pull/20077/files/1d10dd5b..974b6b08

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=20077&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=20077&range=02-03

  Stats: 1640 lines in 65 files changed: 1034 ins; 342 del; 264 mod
  Patch: https://git.openjdk.org/jdk/pull/20077.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20077/head:pull/20077

PR: https://git.openjdk.org/jdk/pull/20077