[turbofan] push virtual register field down to InstructionOperand

src/compiler/instruction.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/common-operator.h"
 #include "src/compiler/graph.h"
 #include "src/compiler/instruction.h"
 
 namespace v8 {
 namespace internal {
@@ skipping 32 matching lines @@
     case InstructionOperand::IMMEDIATE:
       return os << "[immediate:" << op.index() << "]";
     case InstructionOperand::STACK_SLOT:
       return os << "[stack:" << op.index() << "]";
     case InstructionOperand::DOUBLE_STACK_SLOT:
       return os << "[double_stack:" << op.index() << "]";
     case InstructionOperand::REGISTER:
       return os << "[" << conf->general_register_name(op.index()) << "|R]";
     case InstructionOperand::DOUBLE_REGISTER:
       return os << "[" << conf->double_register_name(op.index()) << "|R]";
+    case InstructionOperand::INVALID:
+      return os << "(x)";
   }
   UNREACHABLE();
   return os;
 }
 
 
 template <InstructionOperand::Kind kOperandKind, int kNumCachedOperands>
 SubKindOperand<kOperandKind, kNumCachedOperands>*
     SubKindOperand<kOperandKind, kNumCachedOperands>::cache = NULL;
 
@@ skipping 671 matching lines @@
       os << " B" << succ_block->id();
     }
     os << "\n";
   }
   return os;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8