RFR: 8326135: Enhance adlc to report unused operands [v4]

[Vladimir Kozlov]

On Fri, 23 Feb 2024 06:12:36 GMT, kuaiwei <duke at openjdk.org> wrote:

>> The rule is applied to general JDK sources and not just VM.
>> Please, check "C++ Standard Library" in `hotspot-style` Vladimir pointed and see if listed issues there applied to your changes.
>
> Ok, I will add a hashset implementation.

@kuaiwei  our general consensus is that you can use STL here since it is separate from VM tool.
@iwanowww do you approve?

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PR Review Comment: https://git.openjdk.org/jdk/pull/17910#discussion_r1500951894