executor: fix wrong index hash join when hash col is enum (#28032)

[ti-srebot]

cherry-pick #28032 to release-5.1
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/28081

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

git push [email protected]:ti-srebot/tidb.git pr/28081:release-5.1-c103310663fa

---

Signed-off-by: lzmhhh123 [email protected]

What problem does this PR solve?

Issue Number: close #27893

What is changed and how it works?

What's Changed:

How it Works:

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 wrong index hash join when hash col is enum.

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• XuHuaiyu
• qw4990

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[ti-srebot]

/run-all-tests

[ti-srebot]

@lzmhhh123 you're already a collaborator in bot's repo.

[XuHuaiyu]

LGTM

[zhouqiang-cl]

/merge

[ti-chi-bot]

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

Commit hash: 52ccd82