StatepointLowering.cpp - fix implicit CommandLine.h dependency. NFC.

StatepointLowering defines a cl::opt but don't include CommandLine.h.

llvm/lib/CodeGen/SelectionDAG/StatepointLowering.cpp

@@ -42,6 +42,7 @@
 #include "llvm/IR/Statepoint.h"
 #include "llvm/IR/Type.h"
 #include "llvm/Support/Casting.h"
+#include "llvm/Support/CommandLine.h"
 #include "llvm/Support/MachineValueType.h"
 #include "llvm/Target/TargetMachine.h"
 #include "llvm/Target/TargetOptions.h"