[turbofan] Model arguments object materialization in graph.

src/compiler/ast-graph-builder.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/ast-graph-builder.h"
 
 #include "src/compiler.h"
 #include "src/compiler/ast-loop-assignment-analyzer.h"
 #include "src/compiler/control-builders.h"
 #include "src/compiler/js-type-feedback.h"
@@ skipping 3134 matching lines @@
 
   return local_context;
 }
 
 
 Node* AstGraphBuilder::BuildArgumentsObject(Variable* arguments) {
   if (arguments == NULL) return NULL;
 
   // Allocate and initialize a new arguments object.
   Node* callee = GetFunctionClosure();
-  const Operator* op = javascript()->CallRuntime(Runtime::kNewArguments, 1);
+  CreateArgumentsParameters::Type type =
+      is_strict(language_mode()) || !info()->has_simple_parameters()
+          ? CreateArgumentsParameters::UNMAPPED_ARGUMENTS
+          : CreateArgumentsParameters::MAPPED_ARGUMENTS;
+  const Operator* op = javascript()->CreateArguments(type, 0);
   Node* object = NewNode(op, callee);
 
   // Assign the object to the arguments variable.
   DCHECK(arguments->IsContextSlot() || arguments->IsStackAllocated());
   // This should never lazy deopt, so it is fine to send invalid bailout id.
   FrameStateBeforeAndAfter states(this, BailoutId::None());
   BuildVariableAssignment(arguments, object, Token::ASSIGN, VectorSlotPair(),
                           BailoutId::None(), states);
   return object;
 }
@@ skipping 1084 matching lines @@
     // Phi does not exist yet, introduce one.
     value = NewPhi(inputs, value, control);
     value->ReplaceInput(inputs - 1, other);
   }
   return value;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8