[turbofan] Added the optional Float64RoundTiesEven operator to turbofan.

src/compiler/typer.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/typer.h"
 
 #include "src/base/flags.h"
 #include "src/bootstrapper.h"
 #include "src/compilation-dependencies.h"
 #include "src/compiler/common-operator.h"
@@ skipping 2234 matching lines @@
   return Type::Number();
 }
 
 
 Type* Typer::Visitor::TypeFloat64RoundTiesAway(Node* node) {
   // TODO(sigurds): We could have a tighter bound here.
   return Type::Number();
 }
 
 
+Type* Typer::Visitor::TypeFloat64RoundTiesEven(Node* node) {
+  // TODO(sigurds): We could have a tighter bound here.
+  return Type::Number();
+}
+
+
 Type* Typer::Visitor::TypeFloat64ExtractLowWord32(Node* node) {
   return Type::Signed32();
 }
 
 
 Type* Typer::Visitor::TypeFloat64ExtractHighWord32(Node* node) {
   return Type::Signed32();
 }
 
 
@@ skipping 41 matching lines @@
   }
   if (Type::IsInteger(*value)) {
     return Type::Range(value->Number(), value->Number(), zone());
   }
   return Type::Constant(value, zone());
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8