RFR: 8287024: G1: Improve the API boundary between HeapRegionRemSet and G1CardSet [v2]

[Thomas Schatzl]

> Hi all,
> 
>   can I get reviews for this small refactoring that clarifies the boundaries of what kind of data `HeapRegionRemSet` and `G1CardSet` should operate on?
> 
> * `HeapRegionRemSet` deals with addresses, heap regions
> * `G1CardSet` deals with card indexes in the heap, card regions and cards within card regions
> 
> The `G1CardSet::add_card()` and `G1CardSet::contains_card()` methods are fuzzy about that, they require the caller (`HeapRegionRemSet`) to know about card regions and cards within regions. 
> 
> Testing: gha
> 
> Thanks,
>   Thomas

Thomas Schatzl has updated the pull request incrementally with one additional commit since the last revision:

  ayang review

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/8790/files
  - new: https://git.openjdk.java.net/jdk/pull/8790/files/376cf9ea..bfdd664e

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=8790&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=8790&range=00-01

  Stats: 4 lines in 2 files changed: 0 ins; 0 del; 4 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8790.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8790/head:pull/8790

PR: https://git.openjdk.java.net/jdk/pull/8790