RFR: 8329659: Serial: Extract allowed_dead_ratio from ContiguousSpace [v2]

[Guoxiong Li]

> Hi all,
> 
> This patch moves the `allowed_dead_ratio` related content from `ContiguousSpace` to `DeadSpacer`.
> 
> The tests `make test-tier1_gc` passed locally. Thanks for taking the time to review.
> 
> Best Regards,
> -- Guoxiong

Guoxiong Li has updated the pull request incrementally with one additional commit since the last revision:

  Simplify

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/18661/files
  - new: https://git.openjdk.org/jdk/pull/18661/files/19bb8e87..e51d30c2

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=18661&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=18661&range=00-01

  Stats: 19 lines in 1 file changed: 2 ins; 8 del; 9 mod
  Patch: https://git.openjdk.org/jdk/pull/18661.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18661/head:pull/18661

PR: https://git.openjdk.org/jdk/pull/18661