slice bounds out of range for special json path

[YangKeao]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

select json_extract("{}", "$.\"\\0\\");

2. What did you expect to see? (Required)

mysql> select json_extract("{}", "$.\"\\0\\");
ERROR 3143 (42000): Invalid JSON path expression. The error is around character position 6.

3. What did you see instead (Required)

mysql> select json_extract("{}", "$.\"\\0\\");
ERROR 1105 (HY000): runtime error: slice bounds out of range [:7] with length 6

4. What is your TiDB version? (Required)