R600: Add CF_END

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180123 91177308-0d34-0410-b5e6-96231b3b80d8
R600: Use .AMDGPU.config section to emit stacksize

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180124 91177308-0d34-0410-b5e6-96231b3b80d8