RFR: 8333334: C2: Make result of `Node::dominates` more precise to enhance scalar replacement [v4]

[Qizheng Xing]

On Mon, 1 Jul 2024 06:43:20 GMT, Tobias Hartmann <thartmann at openjdk.org> wrote:

>> Qizheng Xing has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains four commits:
>> 
>>  - Add `@ForceInline` to the IR test.
>>  - Add IR test and update copyright.
>>  - Revert last commit, and push the `LoadNode` back to the worklist to wait for the dead code to be removed.
>>  - Make `Node::dominates` more precise so that iterators of `ConcurrentHashMap` can be scalar replaced.
>
> test/hotspot/jtreg/compiler/c2/irTests/scalarReplacement/ScalarReplacementWithGCBarrierTests.java line 85:
> 
>> 83:         // Must use G1 GC to ensure there is a pre-barrier
>> 84:         // before the first field write.
>> 85:         TestFramework.runWithFlags("-XX:+UseG1GC");
> 
> This will fail if a different GC is selected via the command line. Your test needs a corresponding `@requires`.

Added `@requires vm.gc.G1`.

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PR Review Comment: https://git.openjdk.org/jdk/pull/19496#discussion_r1660643147