8298725: Add BitMap support for reverse iteration

[kimbarrett]

Please review this addition of BitMap::reverse_iterate, which is like
BitMap::iterate but visits the set bits in a range from high index to low.

Testing:
mach5 tier1, which includes running the updated gtests on all Oracle-supported
platform

---

Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• Change must not contain extraneous whitespace
• Commit message must refer to an issue

Issue

• JDK-8298725: Add BitMap support for reverse iteration

Reviewers

• Stefan Karlsson (@stefank - Reviewer) ⚠️ Review applies to d52a34fb
• Axel Boldt-Christmas (@xmas92 - Committer) ⚠️ Review applies to d52a34fb
• Thomas Schatzl (@tschatzl - Reviewer) ⚠️ Review applies to d52a34fb

Reviewing

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Update a local copy of the PR:
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$ git pull https://git.openjdk.org/jdk.git pull/13151/head

Using Skara CLI tools

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$ git pr checkout 13151

View PR using the GUI difftool:
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Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/13151.diff

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[openjdk]

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[mlbridge]

Webrevs

• 01: Full - Incremental (30462f8b)
• 00: Full (d52a34fb)

[stefank]

Looks good.

[openjdk]

@kimbarrett This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8298725: Add BitMap support for reverse iteration

Reviewed-by: stefank, aboldtch, tschatzl

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[xmas92]

lgtm.

[kimbarrett]

Thanks for reviews @xmas92 , @stefank , and @tschatzl .

[kimbarrett]

/integrate

[openjdk]

Going to push as commit 501b606.

[openjdk]

@kimbarrett Pushed as commit 501b606.

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