fast DDL may be broken when add UK of int handle tables

[lance6716]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

func TestAddUKWithSmallIntHandles(t *testing.T) {
	store := realtikvtest.CreateMockStoreAndSetup(t)
	tk := testkit.NewTestKit(t, store)
	tk.MustExec("drop database if exists small;")
	tk.MustExec("create database small;")
	tk.MustExec("use small;")
	tk.MustExec(`set global tidb_ddl_enable_fast_reorg=1;`)
	tk.MustExec("create table t (a bigint, b int, primary key (a) clustered)")
	tk.MustExec("insert into t values (-9223372036854775808, 1),(-9223372036854775807, 1)")
	tk.MustExec("alter table t add unique index uk(b)")
	tk.MustExec("admin check table t")
}

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

duplicate entry

3. What did you see instead (Required)

        	            	[admin:8223]data inconsistency in table: t, index: uk, handle: -9223372036854775808, index-values:"" != record-values:"handle: -9223372036854775808, values: [KindInt64 1]"

4. What is your TiDB version? (Required)

[lance6716]

because MinRowID may be larger than IntHandle.Encoded()

tidb/br/pkg/lightning/common/key_adapter.go

Line 119 in bdc64e5

MinRowID = EncodeIntRowID(math.MinInt64)