## Summary
The change brings the new registry for symbolic functions in ONNX. The `SymbolicRegistry` class in `torch.onnx._internal.registration` replaces the dictionary and various functions defined in `torch.onnx.symbolic_registry`.
The new registry
- Has faster lookup by storing only functions in the opset version they are defined in
- Is easier to manage and interact with due to its class design
- Builds the foundation for the more flexible registration process detailed in #83787
Implementation changes
- **Breaking**: Remove `torch.onnx.symbolic_registry`
- `register_custom_op_symbolic` and `unregister_custom_op_symbolic` in utils maintain their api for compatibility
- Update _onnx_supported_ops.py for doc generation to include quantized ops.
- Update code to register python ops in `torch/csrc/jit/passes/onnx.cpp`
## Profiling results
-0.1 seconds in execution time. -34% time spent in `_run_symbolic_function`. Tested on the alexnet example in public doc.
### After
```
└─ 1.641 export <@beartype(torch.onnx.utils.export) at 0x7f19be17f790>:1
└─ 1.641 export torch/onnx/utils.py:185
└─ 1.640 _export torch/onnx/utils.py:1331
├─ 0.889 _model_to_graph torch/onnx/utils.py:1005
│ ├─ 0.478 _optimize_graph torch/onnx/utils.py:535
│ │ ├─ 0.214 PyCapsule._jit_pass_onnx_graph_shape_type_inference <built-in>:0
│ │ │ [2 frames hidden] <built-in>
│ │ ├─ 0.190 _run_symbolic_function torch/onnx/utils.py:1670
│ │ │ └─ 0.145 Constant torch/onnx/symbolic_opset9.py:5782
│ │ │ └─ 0.139 _graph_op torch/onnx/_patch_torch.py:18
│ │ │ └─ 0.134 PyCapsule._jit_pass_onnx_node_shape_type_inference <built-in>:0
│ │ │ [2 frames hidden] <built-in>
│ │ └─ 0.033 [self]
```
### Before
### Start up time
The startup process takes 0.03 seconds. Calls to `inspect` will be eliminated when we switch to using decorators for registration in #84448
Pull Request resolved: https://github.com/pytorch/pytorch/pull/84382
Approved by: https://github.com/AllenTiTaiWang, https://github.com/BowenBao
Reduce circular dependencies
- Lift constants and flags from `symbolic_helper` to `_constants` and `_globals`
- Standardized constant naming to make it consistant
- Make `utils` strictly dependent on `symbolic_helper`, removing inline imports from symbolic_helper
- Move side effects from `utils` to `_patch_torch`
Pull Request resolved: https://github.com/pytorch/pytorch/pull/77142
Approved by: https://github.com/garymm, https://github.com/BowenBao
