Add NativeFunction.signature and kind. (#45131)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/45131
These make it easier to group native functions together and determine
what kind of native function it is (inplace/out/functional). Currently
they are not used but they may be useful for tools.autograd porters.
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Test Plan: Imported from OSS
Reviewed By: zhangguanheng66
Differential Revision: D23872526
Pulled By: ezyang
fbshipit-source-id: 1d6e429ab9a1f0fdb764be4228c5bca4dce8f24e
