From: @yanglf1121
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: @huaweib
Reviewed-by: @kisnwang,@zhoufeng54
Signed-off-by: @zhoufeng54

From: @liangzhibo
Reviewed-by: @ginfung,@zh_qh
Signed-off-by: @zh_qh

From: @wangrao124
Reviewed-by: @wuxuejian
Signed-off-by:

From: @huangbo77
Reviewed-by: @wuxuejian,@kisnwang
Signed-off-by: @wuxuejian

From: @zhangzhewei01
Reviewed-by: 
Signed-off-by:

From: @he-botao
Reviewed-by: 
Signed-off-by:

From: @caojian05
Reviewed-by: @wuxuejian,@oacjiewen
Signed-off-by: @wuxuejian

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

From: @wangrao124
Reviewed-by: @wuxuejian,@kisnwang
Signed-off-by: @wuxuejian

From: @wuxuejian
Reviewed-by: @kisnwang,@guoqi1024,@c_34
Signed-off-by: @c_34

增加测试用例

修改测试用例

修改测试用例

修改算子实现，alpha 写死为 1.0

修改算子实现，alpha 写死为 1
修改算子注册

修改算子实现，dy 和 y 搞反了

修改测试代码

修改算子实现

修改算子实现，float16 单独走一个分支

修改算子实现，前端的 float 转换为double

修改算子实现，改回来了

修改算子实现，float16 转换为 Eigen 库中的 half

修改算子实现，float16 转换为 Eigen 库中的 half

修改算子实现，float16 转换为 Eigen 库中的 half

修改算子实现 在单独的文件中实现 EluGrad

修改算子实现 在单独的文件中实现 EluGrad

修改算子实现 在单独的文件中实现 EluGrad

修改算子实现 在单独的文件中实现 EluGrad

格式化代码

修改 pylint 错误

更新注释信息

删除未使用的私有变量

删除未使用的私有变量

From: @yanglf1121
Reviewed-by: @wuxuejian,@kisnwang
Signed-off-by: @wuxuejian

From: @xukailun_1
Reviewed-by: @wuxuejian,@liangchenghui
Signed-off-by: @wuxuejian

From: @david-he91
Reviewed-by: 
Signed-off-by:

From: @wuxuejian
Reviewed-by: @kisnwang,@liangchenghui
Signed-off-by: @liangchenghui

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

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

From: @zhao_ting_v
Reviewed-by: @wuxuejian,@liangchenghui
Signed-off-by: @liangchenghui

From: @yang_chun
Reviewed-by: @wuxuejian,@c_34
Signed-off-by: @c_34

From: @yanglf1121
Reviewed-by: @kisnwang
Signed-off-by:

From: @yuanwei66
Reviewed-by: @c_34,@wuxuejian
Signed-off-by: @wuxuejian