expression: prevent function of castYearAsTime from pushing down to Ti… (#25975)

[ti-srebot]

cherry-pick #25975 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/26370

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

git push [email protected]:ti-srebot/tidb.git pr/26370:release-5.1-39a56e5c4df0

---

What problem does this PR solve?

Issue Number: pingcap/tiflash#1964

Problem Summary:

The type of year operation with the type of date is wrong, for example:

create table t(a year,b date);
insert into t values(2005,"2004-10-10"),(2015,"2018-03-27");
alter table t set tiflash replica 1;
select * from t where a>b;

except:

+------+------------+
| a    | b          |
+------+------------+
| 2005 | 2004-10-10 |
+------+------------+

actual:

empty

What is changed and how it works?

the problem is because that the column a of type year handled by function of castIntAsTime is pushed down to Tiflash.
Tiflash cannot recognize type year without field type, so cast the column a as time incorrectly.
Temporarily stop pushing down the function of castIntAsTime to TiFlash to get the correctly record.

Release note

• no release note

[ti-srebot]

/run-all-tests

[ti-srebot]

@mengxin9014 please accept the invitation then you can push to the cherry-pick pull requests.
https://github.com/ti-srebot/tidb/invitations

[AilinKid]

/lgtm

[LittleFall]

LGTM

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• AilinKid
• LittleFall

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[LittleFall]

/merge

[ti-chi-bot]

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

Commit hash: 5f42ce3