Revert "Fully quantize Fairseq transformer (#1993)" (#2032)
Revert "Fully quantize Fairseq transformer (#1993)" (#2032)

Summary:
This reverts commit 6379573c9e56620b6b4ddeb114b030a0568ce7fe.

It doesn't tie weights and breaks old checkpoints.
Pull Request resolved: https://github.com/pytorch/fairseq/pull/2032

Reviewed By: cndn, ngoyal2707

Differential Revision: D21141945

Pulled By: myleott

fbshipit-source-id: b2f2ce8092a1bf8bcd6a7e422a69306e342b8cdd

pytorch/fairseq,pytorch/fairseq,pytorch/fairseq