quantized hardsigmoid, take 2 (#34959)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/34959
Adds quantized implementation of hardsigmoid.
Original PR was https://github.com/pytorch/pytorch/pull/34607 and had to
be reverted for a test breakage, trying again.
Test Plan:
tests
benchmarks
Imported from OSS
Differential Revision: D20514212
fbshipit-source-id: cc7ae3b67757e2dde5c313c05ce60a0f2625d961
