R600/SI: Use unordered not equal instructions

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224065 91177308-0d34-0410-b5e6-96231b3b80d8
R600/SI: Make more unordered comparisons legal

This saves a second compare and an and / or by using
the unordered comparison instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224066 91177308-0d34-0410-b5e6-96231b3b80d8
R600/SI: Use unordered equal instructions

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224067 91177308-0d34-0410-b5e6-96231b3b80d8