Enable Tensor.random_(from, to) for half on CPU (#34030)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/34030
Test Plan: Imported from OSS
Differential Revision: D20182412
Pulled By: pbelevich
fbshipit-source-id: b7439e6d66e1c0b9ffa8b397cab057c9146f5714
