[function](vec)use const_col to opt current functions.

[zclllyybb]

Proposed Changes

before:

mysql [ssb]>select count(now()) from lineorder;
+--------------+
| count(now()) |
+--------------+
|    600037902 |
+--------------+
1 row in set (0.96 sec)

mysql [ssb]>select count(curdate()) from lineorder;
+------------------+
| count(curdate()) |
+------------------+
|        600037902 |
+------------------+
1 row in set (0.95 sec)

after:

mysql [ssb]>select count(now()) from lineorder;
+--------------+
| count(now()) |
+--------------+
|    600037902 |
+--------------+
1 row in set (0.85 sec)

mysql [ssb]>select count(curdate()) from lineorder;
+------------------+
| count(curdate()) |
+------------------+
|        600037902 |
+------------------+
1 row in set (0.88 sec)

Problem Summary

The changes are like https://github.com/apache/doris/pull/16953 , apply to CurrentDate and CurrentDateTime.

Checklist(Required)

• [ ] Does it affect the original behavior
• [ ] Has unit tests been added
• [ ] Has document been added or modified
• [ ] Does it need to update dependencies
• [x] Is this PR support rollback (If NO, please explain WHY)

[zclllyybb]

run buildall

[github-actions[bot]]

clang-tidy review says "All clean, LGTM! :+1:"

[zclllyybb]

run p0

[cambyzju]

Could you also give some results before and after, like pr https://github.com/apache/doris/pull/16953

[zclllyybb]

run p0

[github-actions[bot]]

clang-tidy review says "All clean, LGTM! :+1:"

[zclllyybb]

run buildall

[zclllyybb]

run p0

[zclllyybb]

run p0

[zclllyybb]

run p0

[zclllyybb]

run buildall

[github-actions[bot]]

clang-tidy review says "All clean, LGTM! :+1:"

[github-actions[bot]]

PR approved by at least one committer and no changes requested.

[github-actions[bot]]

PR approved by anyone and no changes requested.