[turbofan] Initial attempt to cleanup Node and related classes.

src/compiler/machine-operator-reducer.cc

Index: src/compiler/machine-operator-reducer.cc
diff --git a/src/compiler/machine-operator-reducer.cc b/src/compiler/machine-operator-reducer.cc
index 9496e10dd5527f9c5ec67cd7ec2062a7991d9369..516daec88e61d5778f0ba2c9dc1fdcec0cc7fabb 100644
--- a/src/compiler/machine-operator-reducer.cc
+++ b/src/compiler/machine-operator-reducer.cc
@@ -130,7 +130,7 @@ Node* MachineOperatorReducer::Uint32Div(Node* dividend, uint32_t divisor) {
 Reduction MachineOperatorReducer::Reduce(Node* node) {
   switch (node->opcode()) {
     case IrOpcode::kProjection:
-      return ReduceProjection(OpParameter<size_t>(node), node->InputAt(0));
+      return ReduceProjection(ProjectionIndexOf(node->op()), node->InputAt(0));
     case IrOpcode::kWord32And:
       return ReduceWord32And(node);
     case IrOpcode::kWord32Or: