planner: remove bce in the attach2Task (#59689)

Author: hawkingrei

pkg/planner/core/task.go

@@ -209,8 +209,8 @@ func (p *PhysicalHashJoin) Attach2Task(tasks ...base.Task) base.Task {
 	if p.storeTp == kv.TiFlash {
 		return p.attach2TaskForTiFlash(tasks...)
 	}
-	lTask := tasks[0].ConvertToRootTask(p.SCtx())
 	rTask := tasks[1].ConvertToRootTask(p.SCtx())
+	lTask := tasks[0].ConvertToRootTask(p.SCtx())
 	p.SetChildren(lTask.Plan(), rTask.Plan())
 	task := &RootTask{}
 	task.SetPlan(p)
@@ -391,8 +391,8 @@ func (p *PhysicalHashJoin) convertPartitionKeysIfNeed(lTask, rTask *MppTask) (*M
 }
 
 func (p *PhysicalHashJoin) attach2TaskForMpp(tasks ...base.Task) base.Task {
-	lTask, lok := tasks[0].(*MppTask)
 	rTask, rok := tasks[1].(*MppTask)
+	lTask, lok := tasks[0].(*MppTask)
 	if !lok || !rok {
 		return base.InvalidTask
 	}
@@ -499,8 +499,8 @@ func (p *PhysicalHashJoin) attach2TaskForMpp(tasks ...base.Task) base.Task {
 }
 
 func (p *PhysicalHashJoin) attach2TaskForTiFlash(tasks ...base.Task) base.Task {
-	lTask, lok := tasks[0].(*CopTask)
 	rTask, rok := tasks[1].(*CopTask)
+	lTask, lok := tasks[0].(*CopTask)
 	if !lok || !rok {
 		return p.attach2TaskForMpp(tasks...)
 	}