expression: fix a bug when comparing bit with string (#11654)

[sre-bot]

cherry-pick #11654 to release-2.1

---

What problem does this PR solve?

Issue: #11647
When a bit column compare with a constant string, it gets a wrong result.
Befor the pr:

mysql> create table xx (b bit(1));
Query OK, 0 rows affected (0.01 sec)

mysql> insert into xx values (b'1');
Query OK, 1 row affected (0.00 sec)

mysql> select count(*) from xx where b='1';
+----------+
| count(*) |
+----------+
|        0 |
+----------+
1 row in set (0.00 sec)

This pr:

mysql> create table xx (b bit(1));
Query OK, 0 rows affected (0.01 sec)

mysql> insert into xx values (b'1');
Query OK, 1 row affected (0.00 sec)

mysql> select count(*) from xx where b='1';
+----------+
| count(*) |
+----------+
|        1 |
+----------+
1 row in set (0.00 sec)

What is changed and how it works?

The reason is that we select a wrong target field type in function RefineComparedConstant.
Before this pr, the target field is TypeBit, and convert '1' to 49.
In fact, the target field shoule be an int type in this situation, and convert '1' to 1.
In this pr, I change the target field to TypeLonglong.

Check List

Tests

• Unit test
• Manual test (add detailed scripts or steps below)

Code changes

• Has exported function/method change

Side effects

• Increased code complexity

Related changes

• Need to cherry-pick to the release branch

[sre-bot]

/run-all-tests

[qw4990]

LGTM

[zz-jason]

LGTM

[sre-bot]

/run-all-tests