AMDGPU: Fold CI-specific complex SMRD patterns into existing complex patterns

This is just a cleanup. Also, it adds checking that ByteCount is aligned to 4.

Reviewers: arsenm, nhaehnle, tstellarAMD

Subscribers: kzhuravl, wdng, yaxunl, tony-tye

Differential Revision: https://reviews.llvm.org/D28994

llvm-svn: 303658