RFR: 8377165: G1: Introduce common G1 GC Mark to collect scoped objects [v2]

[Thomas Schatzl]

> Hi all,
> 
>   this change factors out the initial scoped objects common to g1 young and full gc into `G1GCMark` to avoid duplication and ordering issues.
> 
> All other scoped objects (maybe but `G1HeapPrinterMark`) are specific to the separate collectors. Not sure it is worth commonalizing them.
> 
> Testing: gha
> 
> Thanks,
>   Thomas

Thomas Schatzl has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains four commits:

 - Merge branch 'master' into 8377165-common-gc-mark
 - * fix whitespace
 - * fix copyright
 - 8377165
   
   Hi all,
   
     this change factors out the initial scoped objects common to g1 young and full gc into `G1GCMark` to avoid duplication and ordering issues.
   
   Testing: gha
   
   Thanks,
     Thomas

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

Changes: https://git.openjdk.org/jdk/pull/29568/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=29568&range=01
  Stats: 60 lines in 5 files changed: 21 ins; 29 del; 10 mod
  Patch: https://git.openjdk.org/jdk/pull/29568.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29568/head:pull/29568

PR: https://git.openjdk.org/jdk/pull/29568