*: inconsistency between prepare execute and normal sql in rc or for update read when infoSchema is changed

[SpadeA-Tang]

Bug Report

In Rc or For-update-read, when information schema is changed, there may be some inconsistencies between prepare-execute and normal sql.

1. Minimal reproduce step (Required)

func TestInconsistency(t *testing.T) {
	store, clean := testkit.CreateMockStore(t)
	defer clean()

	tk1 := testkit.NewTestKit(t, store)
	tk2 := testkit.NewTestKit(t, store)
	tk1.MustExec("use test")
	tk2.MustExec("use test")

	tk1.MustExec("drop table if exists t1")
	tk1.MustExec("create table t1(id int primary key, c int)")
	tk1.MustExec("insert into t1 values(1, 1), (2, 2)")

	tk1.MustExec("prepare s from 'select * from t1'")

	tk1.MustExec("set tx_isolation='READ-COMMITTED'")
	tk1.MustExec("begin pessimistic")

	tk1.MustQuery("execute s").Check(testkit.Rows("1 1", "2 2"))

	// Change infoSchema
	tk2.MustExec("alter table t1 drop column c")

	tk1.MustQuery("select * from t1").Check(testkit.Rows("1 1", "2 2"))
	// It should be consistent with above
	tk1.MustQuery("execute s").Check(testkit.Rows("1", "2"))
}

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

The results of execute s and select * from t1 are different even though they should be the same.

3. What did you see instead (Required)

4. What is your TiDB version? (Required)

dce5064