util: fix memory.reArrangeFallback cpu usage (#30414)

[ti-srebot]

cherry-pick #30414 to release-5.3
You can switch your code base to this Pull Request by using git-extras:

# In tidb repo:
git pr https://github.com/pingcap/tidb/pull/34005

After apply modifications, you can push your change to this PR via:

git push git@github.com:ti-srebot/tidb.git pr/34005:release-5.3-b5de819d00be

---

What problem does this PR solve?

Issue Number: close #30353

Problem Summary:

What is changed and how it works?

In my machine, this pr reduce execution time of the sql.
Before this pr: 2.5s+
After this pr: 0.3~0.4s

Profiles:

reArrangeFallback will not use too many cpu

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Changes MySQL compatibility

Release note

Fix the problem of high use of reArrangeFallback cpu.

[ti-chi-bot]

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[ti-chi-bot]

@ti-srebot: This cherry pick PR is for a release branch and has not yet been approved by release team.
Adding the do-not-merge/cherry-pick-not-approved label.

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[ti-srebot]

/run-all-tests

[ti-srebot]

@wshwsh12 you're already a collaborator in bot's repo.

[VelocityLight]

This pull request is closed because the related issue is triaged "Won't Fix".
If it's still needed, you can reopen it or just regenerate it using bot,
see:

• https://prow.tidb.io/command-help#cherrypick
• https://book.prow.tidb.net/#/plugins/cherrypicker

You can find more details at:

• https://internals.tidb.io/t/topic/785