Rename function parameters to avoid [-Werror,-Wshadow] (#30276)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/30276
### Summary
When building PyTorch for iOS in BUCK, the compiler complains about the ivar shadowing
```
/Users/taox/fbsource/xplat/caffe2/aten/src/ATen/core/dispatch/Dispatcher.h:184:144: error: declaration shadows a field of 'c10::Dispatcher' [-Werror,-Wshadow]
inline Return Dispatcher::doCallUnboxed(const DispatchTable& dispatchTable, const LeftRight<ska::flat_hash_map<TensorTypeId, KernelFunction>>& backendFallbackKernels_, Args... args) const {
^
/Users/taox/fbsource/xplat/caffe2/aten/src/ATen/core/dispatch/Dispatcher.h:134:63: note: previous declaration is here
LeftRight<ska::flat_hash_map<TensorTypeId, KernelFunction>> backendFallbackKernels_;
```
This happens because the internal iOS compiler enforces the `[-Werror, -Wshadow]` on every source file when compiling. Say in `benchmark.mm` we import `<torch/script.h>`, then it'll leads all the way to `Dispatcher.h`
```
In file included from Apps/Internal/PyTorchPlayground/PyTorchPlayground/Application/Benchmark/Benchmark.mm:6:
In file included from /Users/taox/fbsource/xplat/caffe2/aten/src/ATen/ATen.h:5:
In file included from /Users/taox/fbsource/xplat/caffe2/aten/src/ATen/Context.h:4:
In file included from /Users/taox/fbsource/xplat/caffe2/aten/src/ATen/Tensor.h:12:
In file included from buck-out/cells/fbsource/gen/xplat/caffe2/TensorMethods.h/TensorMethods.h:10:
/Users/taox/fbsource/xplat/caffe2/aten/src/ATen/core/dispatch/Dispatcher.h
```
It'd be better to have a separate name for function parameters.
cc shoumikhin
Test Plan: Imported from OSS
Differential Revision: D18649116
Pulled By: xta0
fbshipit-source-id: 19f50b7a23c11dedcafc2ac2d85b45ae4999be2f
