Revert "[AMDGPU] Fix DPP combiner"

This reverts commit e3e2923a39cbec3b3bc3a7d3f0e9a77a4115080e, svn revision rL350721

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@350730 91177308-0d34-0410-b5e6-96231b3b80d8
7 files changed