[PyTorch] NestedTensor kernels for {r,g}elu{,_}
Pull Request resolved: https://github.com/pytorch/pytorch/pull/75370
These are simple element-wise ops it's convenient to be able to use with NestedTensor.
Differential Revision: [D35448205](https://our.internmc.facebook.com/intern/diff/D35448205/)
Approved by: https://github.com/ngimel
