pytorch

968d7ee4 - [structured] Preserve computed elements from meta func to impl (#61746)

[structured] Preserve computed elements from meta func to impl (#61746) Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/61746 **Summary** This commit introduces a new feature for structured kernels that allows kernels to declare quantities as "precomputed" in `native_functions.yaml`, compute them once in the `meta` function and reuse them again in the `impl`. The names and types of these quantities are used to generate code for a struct containing them that the `meta` function must return. In the case of a handful of surveyed kernels (`all,`, `any`, `avg_pool2d`), these quantities that are used both in the `meta` and `impl` have the same meaning as certain kernel arguments and in fact supersede them. Accordingly, the correspondence between a kernel argument and the precomputed elements that supersede it is also captured in `native_functions.yaml`. This information is used to unpack the struct returned by `meta` and pass its contents correctly to the `impl` function. The primary goal is to avoid recompute and enhance developer experience (e.g. sometimes people can forget to compute these elements while porting a kernel). Test Plan: Imported from OSS Reviewed By: tugsbayasgalan Differential Revision: D30407831 Pulled By: SplitInfinity fbshipit-source-id: 00975525ea373721fe52d06f75cd4ac91f3dc556