RFR: 8362278: G1: Consolidate functions for recording pause start time [v2]

[Ivan Walulya]

> Hi,
> 
> Please review this refactoring change to unify the recording of GC Pause start-time.
> 
> Testing: Tier 1

Ivan Walulya has updated the pull request incrementally with one additional commit since the last revision:

  Thomas Review

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/26323/files
  - new: https://git.openjdk.org/jdk/pull/26323/files/6094a16c..f5ed7d19

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=26323&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=26323&range=00-01

  Stats: 20 lines in 6 files changed: 0 ins; 0 del; 20 mod
  Patch: https://git.openjdk.org/jdk/pull/26323.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26323/head:pull/26323

PR: https://git.openjdk.org/jdk/pull/26323