[turbofan] Add a Simplified::CheckMaps instruction.

src/compiler/operator-properties.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/operator-properties.h"
 
 #include "src/compiler/js-operator.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/opcodes.h"
 
@@ skipping 77 matching lines @@
 
     // Compare operators that can deopt in the middle the operation (e.g.,
     // as a result of lazy deopt in ToNumber conversion) need a second frame
     // state so that we can resume before the operation.
     case IrOpcode::kJSGreaterThan:
     case IrOpcode::kJSGreaterThanOrEqual:
     case IrOpcode::kJSLessThan:
     case IrOpcode::kJSLessThanOrEqual:
       return 2;
 
+    // TODO(titzer): is this necessary?
+    case IrOpcode::kCheckMaps:
+      return 1;
+
     default:
       return 0;
   }
 }
 
 
 // static
 int OperatorProperties::GetTotalInputCount(const Operator* op) {
   return op->ValueInputCount() + GetContextInputCount(op) +
          GetFrameStateInputCount(op) + op->EffectInputCount() +
          op->ControlInputCount();
 }
 
 
 // static
 bool OperatorProperties::IsBasicBlockBegin(const Operator* op) {
   Operator::Opcode const opcode = op->opcode();
   return opcode == IrOpcode::kStart || opcode == IrOpcode::kEnd ||
          opcode == IrOpcode::kDead || opcode == IrOpcode::kLoop ||
          opcode == IrOpcode::kMerge || opcode == IrOpcode::kIfTrue ||
          opcode == IrOpcode::kIfFalse || opcode == IrOpcode::kIfSuccess ||
          opcode == IrOpcode::kIfException || opcode == IrOpcode::kIfValue ||
          opcode == IrOpcode::kIfDefault;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8