Feature Request

Is your feature request related to a problem? Please describe:

MySQL doc
https://dev.mysql.com/doc/refman/8.0/en/regexp.html#operator_regexp
TiDB implementation
https://github.com/pingcap/tidb/blob/c81dabd97164d61f21eacf3b3099063eec7f0774/expression/builtin_like.go#L116
Describe the feature you'd like:

Describe alternatives you've considered:

Teachability, Documentation, Adoption, Migration Strategy: