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

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

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[xzhangxian1008]

/rebuild

[xzhangxian1008]

/run-all-tests

[xzhangxian1008]

/run-all-tests

[xzhangxian1008]

/run-unit-test

[xzhangxian1008]

/run-all-tests

[xzhangxian1008]

/run-unit-test

[xzhangxian1008]

/run-all-tests

[xzhangxian1008]

/run-unit-test

[xzhangxian1008]

/run-unit-test

[xzhangxian1008]

/run-all-tests

[xzhangxian1008]

/close

[ti-chi-bot]

@xzhangxian1008: Closed this PR.

In response to this:

/close

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