RFR: 8244505: G1 pause time ratio calculation does not consider Remark/Cleanup pauses [v3]

[Ivan Walulya]

> The computation for long and short term pause time ratios does not include Remark/Cleanup pause times. Isolate updates
> to _prev_collection_pause_end_ms from update_recent_gc_times(), then have all gc pauses (including Remark/Cleanup)
> recorded by update_recent_gc_times(). Patch also includes trivial clean ups to g1Policy.* files. Testing: Tier 1 - 7
> Performance testing did not show any significant changes in performance

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

  Changes made to address reviews from Thomas.

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/183/files
  - new: https://git.openjdk.java.net/jdk/pull/183/files/2e6179a7..75f87d9a

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=183&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=183&range=01-02

  Stats: 21 lines in 3 files changed: 13 ins; 2 del; 6 mod
  Patch: https://git.openjdk.java.net/jdk/pull/183.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/183/head:pull/183

PR: https://git.openjdk.java.net/jdk/pull/183