Results 6 issues of xufei

## Feature Request **Is your feature request related to a problem? Please describe:** **Describe the feature you'd like:** From MySQL 8.0, more [regular expression](https://dev.mysql.com/doc/refman/8.0/en/regexp.html) function is supported, I would like...

type/feature-request
feature/accepted

### First-time contributors' checklist - [x] I've signed [**Contributor License Agreement**](https://cla-assistant.io/pingcap/docs-cn) that's required for repo owners to accept my contribution. ### What is changed, added or deleted? (Required) ### Which...

translation/done
size/XS
lgtm
v8.0

### What problem does this PR solve? Issue Number: close #52903 Problem Summary: ### What changed and how does it work? - move join exec related code to tidb/pkg/executor/join -...

size/XXL
release-note-none

### What problem does this PR solve? Issue Number: ref #53127 Problem Summary: Current, we dispatch row to each partition by the LSB bits in hash value https://github.com/pingcap/tidb/blob/31c1de0b4f30d708de8228aa72c1a0dbff547504/pkg/executor/join/join_row_table.go#L540 And in...

size/XL
release-note-none

### What problem does this PR solve? Issue Number: ref #53127 Problem Summary: ### What changed and how does it work? This pr add tagged pointer in hash join v2....

size/XL
release-note-none
approved
needs-1-more-lgtm

### First-time contributors' checklist - [x] I've signed [**Contributor License Agreement**](https://cla-assistant.io/pingcap/docs-cn) that's required for repo owners to accept my contribution. ### What is changed, added or deleted? (Required) ### Which...

translation/doing
size/M
needs-cherry-pick-release-6.1
needs-cherry-pick-release-6.5
needs-cherry-pick-release-7.1
needs-cherry-pick-release-7.5
needs-cherry-pick-release-8.1
needs-cherry-pick-release-8.2
needs-cherry-pick-release-8.3