RFR: 8286297: G1: Simplify parallel and serial verification code paths [v2]

[Thomas Schatzl]

> Hi all,
> 
>   please review this small change that simplifies the path splitting parallel/serial execution of verification.
> 
> Testing: gha, local testing
> 
> Thanks,
>   Thomas

Thomas Schatzl has updated the pull request incrementally with one additional commit since the last revision:

  ayang review

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/8572/files
  - new: https://git.openjdk.java.net/jdk/pull/8572/files/c328f39a..7e77228d

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=8572&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=8572&range=00-01

  Stats: 9 lines in 1 file changed: 0 ins; 2 del; 7 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8572.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8572/head:pull/8572

PR: https://git.openjdk.java.net/jdk/pull/8572