[turbofan] remove one level of indirection in phi inputs

src/compiler/instruction-selector.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 "src/compiler/instruction-selector.h"
 
 #include "src/compiler/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
 #include "src/compiler/pipeline.h"
@@ skipping 1001 matching lines @@
 
 void InstructionSelector::VisitPhi(Node* node) {
   const int input_count = node->op()->ValueInputCount();
   PhiInstruction* phi = new (instruction_zone())
       PhiInstruction(instruction_zone(), GetVirtualRegister(node),
                      static_cast<size_t>(input_count));
   sequence()->InstructionBlockAt(current_block_->GetRpoNumber())->AddPhi(phi);
   for (int i = 0; i < input_count; ++i) {
     Node* const input = node->InputAt(i);
     MarkAsUsed(input);
-    phi->Extend(instruction_zone(), GetVirtualRegister(input));
+    phi->SetInput(static_cast<size_t>(i), GetVirtualRegister(input));
   }
 }
 
 
 void InstructionSelector::VisitProjection(Node* node) {
   OperandGenerator g(this);
   Node* value = node->InputAt(0);
   switch (value->opcode()) {
     case IrOpcode::kInt32AddWithOverflow:
     case IrOpcode::kInt32SubWithOverflow:
@@ skipping 179 matching lines @@
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {
   return MachineOperatorBuilder::Flag::kNoFlags;
 }
 
 #endif  // !V8_TURBOFAN_BACKEND
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8