Fix fall outs from my recent change on how carry bit is modeled during isel.

Fix fall outs from my recent change on how carry bit is modeled during isel.
Now the 'S' instructions, e.g. ADDS, treat S bit as optional operand as well.
Also fix isel hook to correctly set the optional operand.
rdar://10073745

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139157 91177308-0d34-0410-b5e6-96231b3b80d8