RFR: 8269295: Verification time before/after young collection only covers parts of the verification [v3]

[Thomas Schatzl]

> Hi all,
> 
>   can I have reviews for this change that makes "Verify Before/After GC" contain all young collection time instead only a (large) part.
> 
> This change also removed some unnecessary and unused return values. They can certainly be re-added if necessary.
> 
> Testing: tier1
> 
> Thanks,
>   Thomas
> 
> Note: this depends on PR4586.

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' of https://git.openjdk.java.net/jdk into 8269295-verify-time-only-covers-parts
 - Initial implementation
 - Fix young gc verify stages
 - Initial implementation

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

Changes: https://git.openjdk.java.net/jdk/pull/4587/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=4587&range=02
  Stats: 28 lines in 3 files changed: 12 ins; 12 del; 4 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4587.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4587/head:pull/4587

PR: https://git.openjdk.java.net/jdk/pull/4587