Revert of Remove register index/code indirection

src/compiler/code-generator.cc

 // Copyright 2013 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/code-generator.h"
 
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/pipeline.h"
 #include "src/frames-inl.h"
@@ skipping 209 matching lines @@
       frame()->GetTotalFrameSlotCount() - frame()->GetSpillSlotCount();
   for (auto& operand : references->reference_operands()) {
     if (operand.IsStackSlot()) {
       int index = StackSlotOperand::cast(operand).index();
       DCHECK(index >= 0);
       // Safepoint table indices are 0-based from the beginning of the spill
       // slot area, adjust appropriately.
       index -= stackSlotToSpillSlotDelta;
       safepoint.DefinePointerSlot(index, zone());
     } else if (operand.IsRegister() && (kind & Safepoint::kWithRegisters)) {
-      Register reg = RegisterOperand::cast(operand).GetRegister();
+      Register reg =
+          Register::FromAllocationIndex(RegisterOperand::cast(operand).index());
       safepoint.DefinePointerRegister(reg, zone());
     }
   }
 }
 
 
 bool CodeGenerator::IsMaterializableFromFrame(Handle<HeapObject> object,
                                               int* offset_return) {
   if (linkage()->GetIncomingDescriptor()->IsJSFunctionCall()) {
     if (info()->has_context() && object.is_identical_to(info()->context()) &&
@@ skipping 423 matching lines @@
     : masm_(gen->masm()), next_(gen->ools_) {
   gen->ools_ = this;
 }
 
 
 OutOfLineCode::~OutOfLineCode() {}
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8