RFR: 8318507: G1: Improve remset clearing for humongous candidates [v2]

[Thomas Schatzl]

> Hi all,
> 
>   please review this small cleanup that merges two calls to `HeapRegionRemSet::clear()/HeapRegionRemSet::set_state_complete()` to a single call to `clear()` with appropriate parameters.
> 
> Also remove now obsolete asserts that are done in `clear()` already; actually the second one is wrong, there may be code roots attached to the region.
> 
> Testing: gha, tier1-5 almost done
> 
> Thanks,
>   Thomas

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

  add assert

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/16270/files
  - new: https://git.openjdk.org/jdk/pull/16270/files/6af1e899..2af41e00

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=16270&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=16270&range=00-01

  Stats: 3 lines in 1 file changed: 2 ins; 1 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/16270.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16270/head:pull/16270

PR: https://git.openjdk.org/jdk/pull/16270