RFR: 8362278: G1: Consolidate functions for recording pause start time [v3]

[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 suggestion

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/26323/files
  - new: https://git.openjdk.org/jdk/pull/26323/files/f5ed7d19..7d3ea11e

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=26323&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=26323&range=01-02

  Stats: 24 lines in 5 files changed: 7 ins; 10 del; 7 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