Simplify precision-specification in tests. (#37181)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/37181
Now that assertEquals considers dtypes in determining tolerance, most
tests don't need explicitly set precision.
Those that do are a few half precision tests on cuda. In this PR, those
are broken out to be handled explicitly, though we may also want to
consider further loosening the tolerance on half-precision.
Test Plan: Imported from OSS
Differential Revision: D21728402
Pulled By: nairbv
fbshipit-source-id: 85f3daf63f1bdbb5101e8dea8c125f13448ca228
