Move implementation of empty_like for sparse COO (#71103)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/71103
Previously the implementation of empty_like for sparse COO was a
conditional path in generic implementation.
This PR makes use of the Dispatcher and moves the implementation into a
separate function.
cc nikitaved pearu cpuhrsch
Test Plan: Imported from OSS
Reviewed By: jbschlosser
Differential Revision: D33511240
Pulled By: cpuhrsch
fbshipit-source-id: 9a84f82a27e3cf0ac819d867b86df6d10ddf7fa7
