RFR: 8349836: G1: Improve group prediction log message [v2]

[Thomas Schatzl]

> Hi all,
> 
>   please review this minor change to the group prediction log message
> printed with gc+ergo+cset=trace:
> 
>   * add group id to be able to refer to something concrete when discussing results
>   * add total time
>   * fix typo in `bytes_to_cop`
> 
> Testing: gha, local verification
> 
> `Group 10: 5 regions prediction total_time 20.0ms card_rs_length 123456 merge_scan_time 10.2ms code_root_scan_time_ms 5.5ms evac_time_ms 3.7ms other_time 0.3ms bytes_to_copy 1234567`
> 
> instead of
> 
> `Prediction for group with 76 regions, card_rs_length 320, merge_scan_time 0.02ms, code_root_scan_time_ms 0.00ms, evac_time_ms 9.92ms, other_time 45.60ms, bytes_to_cop 61408560`
> 
> 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.org/jdk/pull/23562/files
  - new: https://git.openjdk.org/jdk/pull/23562/files/3c9cd94f..21139f21

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=23562&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=23562&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/23562.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23562/head:pull/23562

PR: https://git.openjdk.org/jdk/pull/23562