Revert of Reland: Remove register index/code indirection

src/hydrogen.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/hydrogen.h"
 
 #include <sstream>
 
 #include "src/allocation-site-scopes.h"
 #include "src/ast-numbering.h"
@@ skipping 13508 matching lines @@
 void HTracer::TraceLiveRange(LiveRange* range, const char* type,
                              Zone* zone) {
   if (range != NULL && !range->IsEmpty()) {
     PrintIndent();
     trace_.Add("%d %s", range->id(), type);
     if (range->HasRegisterAssigned()) {
       LOperand* op = range->CreateAssignedOperand(zone);
       int assigned_reg = op->index();
       if (op->IsDoubleRegister()) {
         trace_.Add(" \"%s\"",
-                   DoubleRegister::from_code(assigned_reg).ToString());
+                   DoubleRegister::AllocationIndexToString(assigned_reg));
       } else {
         DCHECK(op->IsRegister());
-        trace_.Add(" \"%s\"", Register::from_code(assigned_reg).ToString());
+        trace_.Add(" \"%s\"", Register::AllocationIndexToString(assigned_reg));
       }
     } else if (range->IsSpilled()) {
       LOperand* op = range->TopLevel()->GetSpillOperand();
       if (op->IsDoubleStackSlot()) {
         trace_.Add(" \"double_stack:%d\"", op->index());
       } else {
         DCHECK(op->IsStackSlot());
         trace_.Add(" \"stack:%d\"", op->index());
       }
     }
@@ skipping 119 matching lines @@
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 }  // namespace internal
 }  // namespace v8