fastrand: optimize Buf

[zhangyunhao116]

use wyrand, see https://github.com/wangyi-fudan/wyhash.

name                old time/op  new time/op   delta
FastRandBuf-16      18.8ns ± 7%    9.3ns ± 3%  -50.37%  (p=0.000 n=10+9)

What problem does this PR solve?

Issue Number: close #33240

What is changed and how it works?

NONE.

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

None

[ti-chi-bot]

[REVIEW NOTIFICATION]

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• hawkingrei
• tiancaiamao

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[sre-bot]

Code Coverage Details: https://codecov.io/github/pingcap/tidb/commit/c924be3ad3669d2567d93907ed4611af2156c7c8

[tiancaiamao]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: aeaeb3b

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@zhangyunhao116: Your PR was out of date, I have automatically updated it for you.

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