RFR: 8304016: Add BitMap find_last suite of functions [v2]

[Stefan Karlsson]

On Sun, 19 Mar 2023 22:06:53 GMT, Kim Barrett <kbarrett at openjdk.org> wrote:

>> Please review this change that adds functions to BitMap for finding the last
>> set/clear bit in a range.
>> 
>> Testing:
>> mach5 tier1, including new gtesting for the new functions.
>
> Kim Barrett has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - shrink find_first_bit_impl
>  - improve find_last_bit_impl

Thanks for creating this PR. As we have discussed offline, this is not my preferred code style for these functions, but I'm happy to see this functionality being upstreamed, so consider this reviewed.

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Marked as reviewed by stefank (Reviewer).

PR: https://git.openjdk.org/jdk/pull/12988