Data may loss when widen pk if pk is handle

[lidezhu]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

1. create table and wait until tiflash replica is ready.

mysql> create table test.t(a int primary key);
mysql> alter table test.t set tiflash replica 1;
mysql> insert into test.t values(1);

2. disable background schema sync service using tiflash client

>> DBGInvoke __enable_schema_sync_service('false')

3. widen pk

mysql> alter table test.t modify column a bigint;
mysql> insert into test.t values(9223372036854775807);
mysql> select /*+ read_from_storage(tiflash[t]) */ * from test.t;

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

+---------------------+
| a                   |
+---------------------+
|                   1 |
| 9223372036854775807 |
+---------------------+

3. What did you see instead (Required)

+---------------------+
| a                   |
+---------------------+
|                   1 |
|                  -1 |
+---------------------+

4. What is your TiFlash version? (Required)

latest master