R600: Add target nodes for BFM and BFI

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205235 91177308-0d34-0410-b5e6-96231b3b80d8
R600: Add BFE, BFI, and BFM intrinsics to help with writing tests.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205236 91177308-0d34-0410-b5e6-96231b3b80d8