Improve the performance of length and ascii functions (#9345)

[ti-chi-bot]

This is an automated cherry-pick of #9345

What problem does this PR solve?

Issue Number: close #9344

Problem Summary:

What is changed and how it works?

Benchmark from bench_function_string.cpp

           origin         optimized
length    19794917 ns    1824123 ns 985.2%
ascii     20572895 ns    2592171 ns 693.7%

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

[xzhangxian1008]

/retest

[xzhangxian1008]

/retest

[xzhangxian1008]

/run-all-tests

[yibin87]

LGTM

[windtalker]

lgtm

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: windtalker, yibin87

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• OWNERS [windtalker,yibin87]

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-09-06 06:53:49.763854314 +0000 UTC m=+600154.281907238: ☑️ agreed by yibin87.
• 2024-09-06 06:56:06.500365496 +0000 UTC m=+600291.018418424: ☑️ agreed by windtalker.