[AMDGPU] SDWA peephole: enable by default

Reviewers: vpykhtin, rampitec, arsenm

Subscribers: qcolombet, kzhuravl, wdng, nhaehnle, yaxunl, dstuttard, tpr, t-tye

Differential Revision: https://reviews.llvm.org/D31671

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299536 91177308-0d34-0410-b5e6-96231b3b80d8
43 files changed