RFR: 8303362: Serial: Move CardTableRS to serial directory [v2]

[Albert Mingkun Yang]

> Simple refactoring to move a Serial-only file outside `shared` folder. Split into two commits for easier reviewing.
> 
> 1. Move and renaming.
> 2. Sort headers.

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/12789/files
  - new: https://git.openjdk.org/jdk/pull/12789/files/8b31cd34..40184bc0

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=12789&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=12789&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/12789.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12789/head:pull/12789

PR: https://git.openjdk.org/jdk/pull/12789