*: avoid unlock of unlocked mutex panic on TableDeltaMap (#57799)

[ti-chi-bot]

This is an automated cherry-pick of #57799

What problem does this PR solve?

Issue Number: close #57798

Problem Summary:

What changed and how does it work?

It's most likely that unlock of unlocked mutex is caused by the struct assignment that overwrite the mutex field.

goroutine1:
mu.Lock()
                                                            goroutine2:
                                                            mu = &struct{ }   
defer mu.Unlock()                              <- unlock of unlocked mutex

The old code is weird, tdmLock is used to protect TableDeltaMap but it's not goes together with TableDeltaMap.

I wrap TableDeltaMap into a struct and provide Clone() and Visit() function to it.

Just tiny workaround!

Check List

Tests

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

  • I checked and no code files have been changed.

Some kind of data race, not easy to check in the unit test way

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

Please refer to Release Notes Language Style Guide to write a quality release note.

None

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

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Additional details and impacted files

@@               Coverage Diff                @@
##             release-8.1     #59576   +/-   ##
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Flag	Coverage Δ
unit	71.2207% <100.0000%> (?)

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Components	Coverage Δ
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parser	∅ <0.0000%> (?)
br	41.4439% <0.0000%> (?)