Signed-off-by: zhoufeng <zhoufeng54@huawei.com>

From: @HulkTang
Reviewed-by: @zhoufeng54,@jjfeing
Signed-off-by: @jjfeing

From: @liubuyu
Reviewed-by: 
Signed-off-by:

The basic idea is: exploits data dependency to control the execution order
of side-effect operations, and keep the semantics of ANF unchanged.

The ControlDepend primitive is removed and there are two primitives added:

1. UpdateState:
```
  a = Assign(para, value)
```
became:
```
  a = Assign(para, value, u)
  u = UpdateState(u, a)
```

2. Load:
```
  x = Add(para, value)
```
became:
```
  p = Load(para, u)
  x = Add(p, value)
  u = UpdateState(u, p)
```

From: @limingqi107
Reviewed-by: @kisnwang,@cristoval
Signed-off-by: @cristoval

From: @zyli2020
Reviewed-by: @cristoval,@limingqi107
Signed-off-by: @limingqi107

From: @liubuyu
Reviewed-by: 
Signed-off-by:

From: @jojobugfree
Reviewed-by: @kisnwang,@jjfeing
Signed-off-by: @jjfeing

From: @joylvliang
Reviewed-by: 
Signed-off-by:

From: @yao_yf
Reviewed-by: @kisnwang,@jjfeing
Signed-off-by: @jjfeing

From: @yao_yf
Reviewed-by: 
Signed-off-by:

From: @laiyongqiang
Reviewed-by: @kisnwang,@jjfeing
Signed-off-by: @jjfeing

From: @laiyongqiang
Reviewed-by: 
Signed-off-by:

From: @laiyongqiang
Reviewed-by: 
Signed-off-by:

Merge pull request !8286 from laiyongqiang/context_somas