RFR: 8365024: G1: Make G1CollectionSet::_inc_build_state assert-only [v2]

[Thomas Schatzl]

> Hi all,
> 
>   please review this change that makes the `G1CollectionSet::_inc_build_state` member debug/assert-only - it's only ever used in assertions.
> 
> Testing: local compilation, gha
> 
> Thanks,
>   Thomas

Thomas Schatzl has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase.

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Changes:
  - all: https://git.openjdk.org/jdk/pull/26671/files
  - new: https://git.openjdk.org/jdk/pull/26671/files/09b659ed..09b659ed

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=26671&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=26671&range=00-01

  Stats: 0 lines in 0 files changed: 0 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/26671.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26671/head:pull/26671

PR: https://git.openjdk.org/jdk/pull/26671