R600/SI: Also check for FPImm literal constants

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220067 91177308-0d34-0410-b5e6-96231b3b80d8
Fix typo

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220068 91177308-0d34-0410-b5e6-96231b3b80d8