RFR: 8318647: Serial: Refactor BlockOffsetTable [v3]

[Albert Mingkun Yang]

> The diff is too large; maybe it's better to read the new impl directly, which I believe is much easier to follow.
> 
> There is some duplication with G1's implementation, which should probably be dealt with in its own PR.

Albert Mingkun Yang has updated the pull request incrementally with one additional commit since the last revision:

  review

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/16304/files
  - new: https://git.openjdk.org/jdk/pull/16304/files/2d12fb0d..a4f6ea8f

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=16304&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=16304&range=01-02

  Stats: 15 lines in 2 files changed: 4 ins; 10 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/16304.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16304/head:pull/16304

PR: https://git.openjdk.org/jdk/pull/16304