types: fix clustered keyword to hint regexp

[lysu]

Signed-off-by: lysu sulifx@gmail.com

What problem does this PR solve?

Problem Summary:

fix test failure in https://github.com/pingcap/ticdc/pull/1490

il>, ErrCount:0, SnapshotVersion:0"] [schema=clustered_index_test] [query="create database `clustered_index_test`"] [ts=423467362558148621]
[2021/03/11 02:09:52.880 +08:00] [DEBUG] [schema_storage.go:543] ["handle job: "] ["sql query"="create database `clustered_index_test`"] [job="ID:52, Type:create schema, State:done, SchemaState:public, SchemaID:51, TableID:0, RowCount:0, ArgLen:0, start time: 2021-03-11 02:09:50.032 +0800 CST, Err:<nil>, ErrCount:0, SnapshotVersion:0"]
[2021/03/11 02:09:52.881 +08:00] [DEBUG] [changefeed.go:707] ["DDL processed to make special features mysql-compatible"] [query="create database `/*T![clustered_index] clustered */ _index_test`"]
[2021/03/11 02:09:52.955 +08:00] [INFO] [mysql.go:246] ["Exec DDL succeeded"] [sql="create database `/*T![clustered_index] clustered */ _index_test`"]

What is changed and how it works?

What's Changed, How it Works:

add \b

Related changes

• n/a

Check List

Tests

• Unit test

Side effects

• n/a

Release note

• n/a

---

This change is 

[coocood]

/lgtm

[tangenta]

/lgtm

[lysu]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: 0a131bce28e2173263c4cebf22b92c1ccdba7f4e

[lysu]

/lgtm cancel

[coocood]

/lgtm

[ti-chi-bot]

[REVIEW NOTIFICATION]

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• coocood
• tangenta

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[lysu]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: b54bf6e

[lysu]

/run-tics-test

[lysu]

/merge

[Rustin170506]

/merge

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