R600: Constraints input regs of interp_xy,_zw

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183106 91177308-0d34-0410-b5e6-96231b3b80d8
R600: use capital letter for PV channel

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183107 91177308-0d34-0410-b5e6-96231b3b80d8
R600: CALL_FS consumes a stack size entry

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183108 91177308-0d34-0410-b5e6-96231b3b80d8
R600: 3 op instructions have no write bit but the result are store in PV

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@183111 91177308-0d34-0410-b5e6-96231b3b80d8