R600/SI: Set 20-bit immediate byte offset for SMRD on VI

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223614 91177308-0d34-0410-b5e6-96231b3b80d8
R600/SI: Disable VMEM and SMEM clauses by breaking them with S_NOP

This is only a workaround.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223615 91177308-0d34-0410-b5e6-96231b3b80d8