Add Int8Transpose operator (#16382)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/16382
Adding an Int8TransposeOp that inherits from TransposeOp.
Small refactoring to normal TransposeOp to move main logic into a TransposeImpl
function.
Test Plan: int8_test.cc
Reviewed By: supriyar
Differential Revision: D13822715
fbshipit-source-id: a4d61bdf8e4e1d3f2e30b86d325810ed44c21635
