Quantized concatenation (+fused relu). (#21749)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/21749
This is the first version without "requantization"
Reviewed By: jerryzh168
Differential Revision: D15807940
fbshipit-source-id: 19bb0482abed8ed9d1521a3fa1f15bda8e6a6a7c
