[turbofan] Use Node input iterators where possible

src/compiler/branch-elimination.cc

 // Copyright 2015 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 "src/compiler/branch-elimination.h"
 
 #include "src/compiler/js-graph.h"
 #include "src/compiler/node-properties.h"
 #include "src/compiler/simplified-operator.h"
 
@@ skipping 125 matching lines @@
   // Here we rely on having only reducible loops:
   // The loop entry edge always dominates the header, so we can just use
   // the information from the loop entry edge.
   return TakeConditionsFromFirstControl(node);
 }
 
 
 Reduction BranchElimination::ReduceMerge(Node* node) {
   // Shortcut for the case when we do not know anything about some
   // input.
-  for (int i = 0; i < node->InputCount(); i++) {
-    if (node_conditions_.Get(node->InputAt(i)) == nullptr) {
+  for (Node* input : node->inputs()) {
+    if (node_conditions_.Get(input) == nullptr) {
       return UpdateConditions(node, nullptr);
     }
   }
 
   const ControlPathConditions* first = node_conditions_.Get(node->InputAt(0));
   // Make a copy of the first input's conditions and merge with the conditions
   // from other inputs.
   ControlPathConditions* conditions =
       new (zone_->New(sizeof(ControlPathConditions)))
           ControlPathConditions(*first);
@@ skipping 146 matching lines @@
 
 Graph* BranchElimination::graph() const { return jsgraph()->graph(); }
 
 CommonOperatorBuilder* BranchElimination::common() const {
   return jsgraph()->common();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8