TiDB server crashes when executing a query with nested JOIN followed by a simple SELECT query.

## Bug Report

Please answer these questions before submitting your issue. Thanks!

### 1. Minimal reproduce step (Required)
```SQL
-- SCHEMA
CREATE TABLE users (
id INT,
username VARCHAR(100),
email VARCHAR(255),
age INT,
status VARCHAR(20),
created_at TIMESTAMP NULL,
score DOUBLE
);

CREATE TABLE posts (
id INT,
user_id INT,
title VARCHAR(255),
content VARCHAR(1000),
views INT,
likes INT,
created_at TIMESTAMP NULL,
rating DOUBLE
);

CREATE TABLE orders (
id INT,
user_id INT,
amount DOUBLE,
status VARCHAR(20),
created_at TIMESTAMP NULL
);

INSERT INTO users VALUES
(1, 'alice', 'alice@test.com', 20, 'active', '2022-01-01 10:00:00', 88.5),
(2, 'bob', 'bob@test.com', 30, 'active', '2022-01-02 11:00:00', 92.3),
(3, 'carol', NULL, NULL, 'banned','2022-01-03 12:00:00', NULL),
(4, 'dave', 'dave@test.com', 45, 'active', '2022-01-04 13:00:00', 65.2),
(5, NULL, 'null@test.com', 18, 'inactive','2022-01-05 14:00:00', 70.0);

INSERT INTO posts VALUES
(1, 1, 'Hello World', 'First post', 100, 10, '2022-01-10 10:00:00', 4.5),
(2, 1, 'Another Post', NULL, 150, 20, '2022-01-11 11:00:00', 3.0),
(3, 2, 'Bob Post', 'Content', NULL, 5, '2022-01-12 12:00:00', NULL),
(4, 3, NULL, 'Empty', 50, 2, '2022-01-13 13:00:00', 5.0),
(5, 4, 'Last Post', 'Last', 300, 30,'2022-01-14 14:00:00', 4.9);

INSERT INTO orders VALUES
(1, 1, 100.00, 'paid', '2022-02-01 09:00:00'),
(2, 1, 200.50, 'shipped', '2022-02-02 10:00:00'),
(3, 2, NULL, 'failed', '2022-02-03 11:00:00'),
(4, 3, 50.00, 'paid', '2022-02-04 12:00:00'),
(5, 5, 999.99, 'paid', '2022-02-05 13:00:00');

-- TRIGGER SQLs
SELECT COUNT(*)
FROM (
SELECT 1
FROM orders AS ref_0
WHERE ref_0.user_id IS NOT NULL
) AS subq_0
INNER JOIN (
SELECT ref_1.score AS c1
FROM users AS ref_1
WHERE ref_1.id IS NOT NULL
) AS subq_1
LEFT JOIN (
SELECT
ref_3.rating AS c1,
REGEXP_SUBSTR('7i', NULLIF('t', 'a1rag')) AS c2,
UPPER('zj5') AS c3
FROM posts AS ref_3
WHERE TRUE
) AS subq_2
ON subq_1.c1 = subq_2.c1
ON subq_2.c2 <> REGEXP_REPLACE(subq_2.c2, subq_2.c2, subq_2.c3);

-- OUTPUT: ERROR 1105 (HY000): runtime error: invalid memory address or nil pointer dereference

select VERSION();

-- OUTPUT:
ERROR 2013 (HY000): Lost connection to MySQL server during query
No connection. Trying to reconnect...
Connection id: 2097336
Current database: mynewdb

+--------------------+
| VERSION() |
+--------------------+
| 8.0.11-TiDB-v7.5.1 |
+--------------------+
1 row in set (0.01 sec)
```

### 2. What did you expect to see? (Required)
The second query should execute normally and return a result set (possibly empty), without causing any server crash or connection reset.

### 3. What did you see instead (Required)
The server crashed first, then reconnected and returned the result set.

### 4. What is your TiDB version? (Required)
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| tidb_version() |
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Release Version: v7.5.1
Edition: Community
Git Commit Hash: 7d16cc79e81bbf573124df3fd9351c26963f3e70
Git Branch: heads/refs/tags/v7.5.1
UTC Build Time: 2024-02-27 14:28:32
GoVersion: go1.21.6
Race Enabled: false
Check Table Before Drop: false
Store: unistore |
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+