support custom backend · Pull Request !89839 · MindSpore/mindspore

1. support custom backend
---
<!--  Thanks for sending a pull request!  Here are some tips for you:

1) If this is your first time, please read our contributor guidelines: https://gitee.com/mindspore/mindspore/blob/master/CONTRIBUTING.md

2) If you want to contribute your code but don't know who will review and merge, please add label `mindspore-assistant` to the pull request, we will find and do it as soon as possible.
-->

**What type of PR is this?**

/kind task

---

**What does this PR do / why do we need it**:
自定义后端特性
```
┌─────────────────────────────────────────┐
│    Python API (mindspore.graph && jit)  │  ← 用户接口层
├─────────────────────────────────────────┤
│             Pybind11 Bridge             │  ← Python-C++桥接
├─────────────────────────────────────────┤
│             BackendManager              │  ← 多后端管理
│   ┌─────────────────────────────────┐   │
│   │   Plugin Loading & Registry     │   │  ← SO动态加载
│   └─────────────────────────────────┘   │
├─────────────────────────────────────────┤
│       Backend Implementation Layer      │  ← 后端实现层
│   ┌─────────────────────────────────┐   │
│   │               Build             │   │  ← 编译接口
│   │               Run               │   │  ← 执行接口
│   └─────────────────────────────────┘   │
├─────────────────────────────────────────┤
│              device context             │  ← 硬件使能层
└─────────────────────────────────────────┘
```

---

**Which issue(s) this PR fixes**:

Fixes #ICY9OU

---

**Test Plan and Test result：What scenarios were tested, and what were the verification results（Function, performance, reliability, etc.）**：
补齐10+UT，6个st

---

**Self-checklist**:（**请自检，在[ ]内打上x，我们将检视你的完成情况，否则会导致pr无法合入**）

+ - [x] **设计**：PR对应的方案是否已经经过Maintainer评审，方案检视意见是否均已答复并完成方案修改
+ - [x] **测试**：PR中的代码是否已有UT/ST测试用例进行充分的覆盖，新增测试用例是否随本PR一并上库或已经上库
+ - [x] **验证**：PR描述信息中是否已包含对该PR对应的Feature、Refactor、Bugfix的预期目标达成情况的详细验证结果描述
+ - [ ] **接口**：是否涉及对外接口变更，相应变更已得到接口评审组织的通过，API对应的注释信息已经刷新正确
+ - [ ] **文档**：是否涉及官网文档修改，如果涉及请及时提交资料到Doc仓

GVP MindSpore/mindspore

发现个问题

GVPMindSpore/mindspore

搜索帮助

GVP MindSpore/mindspore