(#22827)
Summary:
1. Fix out of range memory access for reduction on all dimensions for non-packed
tensor.
2. Enabling launch config that maps block width to reduction on fastest striding
dimension. This mapping was previously only active when reducing on fastest
striding dimension of packed tensor, which is not necessary.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/22827
Differential Revision: D16271897
Pulled By: zdevito
fbshipit-source-id: 20763f6cf9a58e44ffc0e7ec27724dfec8fe2c5d
