Add LazyBatchNormXd (#51548)
Summary:
This PR implements UninitializedBuffer and LazyBatchnormXd based on https://github.com/pytorch/pytorch/issues/44538. (cc. emcastillo and albanD)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/51548
Reviewed By: zhangguanheng66
Differential Revision: D26276903
Pulled By: albanD
fbshipit-source-id: 0ac706974178363f8af075e59b41d5989418922f
