[Inductor] Track constant's original_fqn mapping (#120524)
When compiling an deserialized ExportedProgram, constant’s original_fqn is not populated(). Highlighted line is missing, And a latter assertion is breaking due to original_fqn missing.
```
constants_info_[0].name = "L__self___w_pre";
constants_info_[0].dtype = static_cast<int32_t>(cached_torch_dtype_float32);
constants_info_[0].offset = 0;
constants_info_[0].data_size = 64;
constants_info_[0].from_folded = false;
constants_info_[0].shape = {4, 4};
constants_info_[0].stride = {4, 1};
// constants_info_[0].original_fqn = "w_pre"; // this line is missing
```
Inductor is relying `dynamo_flat_name_to_original_fqn` to populate the original_fqn field. This field originates from `graph_module.meta["dynamo_flat_name_to_original_fqn"]`, and is set during dynamo tracing. However, when compiling
an deserialized ExportedProgram, we don't do dynamo tracing, thus this field is missing.
As a fix, I maintain AOTI's own mapping for constant tensor's fqn.
Differential Revision: D54097073
Pull Request resolved: https://github.com/pytorch/pytorch/pull/120524
Approved by: https://github.com/chenyang78
