Provide mutators in NodeProperties instead of exposing indicies.

test/cctest/compiler/test-simplified-lowering.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <limits>
 
 #include "src/compiler/control-builders.h"
 #include "src/compiler/generic-node-inl.h"
 #include "src/compiler/graph-visualizer.h"
 #include "src/compiler/node-properties-inl.h"
@@ skipping 690 matching lines @@
       return graph()->NewNode(simplified()->ReferenceEqual(Type::Any()), node,
                               jsgraph.TrueConstant());
     }
   }
 
   Node* Branch(Node* cond) {
     Node* br = graph()->NewNode(common()->Branch(), cond, start);
     Node* tb = graph()->NewNode(common()->IfTrue(), br);
     Node* fb = graph()->NewNode(common()->IfFalse(), br);
     Node* m = graph()->NewNode(common()->Merge(2), tb, fb);
-    ret->ReplaceInput(NodeProperties::FirstControlIndex(ret), m);
+    NodeProperties::ReplaceControlInput(ret, m);
     return br;
   }
 
   Node* Int64Constant(int64_t v) {
     return graph()->NewNode(common()->Int64Constant(v));
   }
 
   SimplifiedOperatorBuilder* simplified() { return &main_simplified_; }
   MachineOperatorBuilder* machine() { return &main_machine_; }
   CommonOperatorBuilder* common() { return &main_common_; }
@@ skipping 642 matching lines @@
 
   Node* store = t.graph()->NewNode(t.simplified()->StoreField(access), t.p0,
                                    t.p1, t.start, t.start);
   t.Effect(store);
   t.Lower();
 
   CHECK_EQ(IrOpcode::kStore, store->opcode());
   CHECK_EQ(t.p0, store->InputAt(0));
   CheckChangeOf(IrOpcode::kChangeTaggedToFloat64, t.p1, store->InputAt(2));
 }