generate inplace/out kernels for xla (#57510)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/57510
This is a re-write of https://github.com/pytorch/pytorch/pull/56835, which is significantly shorter thanks to the data model change in the PR below this one in the stack. See the original description in the linked PR for details.
The functional changes in this PR are the same as in the above linked one, so the description is the same with a few small changes:
- I don't bother generating `at::xla::{op}` entries for CPU fallbacks. After looking around, I see precedent for that. For example, we don't have `at::cpu::{op}` entries for composite ops- if you really want to bypass the dispatcher you need to call `at::compositeimplicitautograd::{op}`. Maybe we should revisit that later if we find an important use case for having full namespace coverage, but that doesn't seem worth half-fixing for external backends in this PR.
Test Plan: Imported from OSS
Reviewed By: navahgar
Differential Revision: D28474364
Pulled By: bdhirsh
fbshipit-source-id: 4d58b60e5debad6f1ff06420597d8df8505b2876
