RFR: 8304716: Clean up G1Policy::calc_max_old_cset_length() [v4]

[Thomas Schatzl]

> Hi all,
> 
>   please review this simplification of `G1Policy::calc_max_old_cset_length()`. It does not seem important to be clever here.
> 
> Depends on #13147.
> 
> 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 10 commits:

 - Fix unintentionally removed documentation
 - Merge branch 'master' into 8304716-calc-max-old-cset-length
 - ayang review2
 - ayang review, break formula a bit
 - just use ceil()
 - initial version
 - Just use ceil()
 - moving cast around
 - fix compilation on windows
 - Initial version

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

Changes: https://git.openjdk.org/jdk/pull/13148/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=13148&range=03
  Stats: 10 lines in 1 file changed: 0 ins; 7 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/13148.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13148/head:pull/13148

PR: https://git.openjdk.org/jdk/pull/13148