[jdk17u-dev] RFR: 8278146: G1: Rework VM_G1Concurrent VMOp to clearly identify it as pause [v3]

[Aleksey Shipilev]

> Clean backport to improve detailed VM diagnostics.
> 
> @tschatzl, are you good with this in 17u?
> 
> Additional testing:
>  - [x] Linux x86_64 fastdebug `tier1`
>  - [x] Linux x86_64 fastdebug `tier2`
>  - [x] Linux x86_64 fastdebug `tier3`

Aleksey Shipilev 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 two additional commits since the last revision:

 - Merge branch 'master' into JDK-8278146-g1-safepoint-names
 - Backport 3a1fca3adf3111a966cb62d926b95acc89b7fe97

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

Changes:
  - all: https://git.openjdk.org/jdk17u-dev/pull/910/files
  - new: https://git.openjdk.org/jdk17u-dev/pull/910/files/3c20e4b8..30c59831

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=910&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=910&range=01-02

  Stats: 2461 lines in 323 files changed: 1988 ins; 210 del; 263 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/910.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/910/head:pull/910

PR: https://git.openjdk.org/jdk17u-dev/pull/910