Add Scalar::type() (#33603)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/33603
This function returns ScalarType based on its value. This is helpful
to avoid code generated in aten_op.h has returned Scalars depending on
arg self to determine its type.
Test Plan: Imported from OSS
Differential Revision: D20100218
Pulled By: ezyang
fbshipit-source-id: 337729a7559e6abb3a16b2a563a2b92aa96c7016
