[turbofan] Added the RoundInt64ToFloat64 instruction to TurboFan.

src/compiler/mips/instruction-selector-mips.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/base/adapters.h"
 #include "src/base/bits.h"
 #include "src/compiler/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
 
@@ skipping 358 matching lines @@
 void InstructionSelector::VisitChangeFloat32ToFloat64(Node* node) {
   VisitRR(this, kMipsCvtDS, node);
 }
 
 
 void InstructionSelector::VisitChangeInt32ToFloat64(Node* node) {
   VisitRR(this, kMipsCvtDW, node);
 }
 
 
+void InstructionSelector::VisitChangeInt64ToFloat64(Node* node) {
+  UNIMPLEMENTED();
+}
+
+
 void InstructionSelector::VisitChangeUint32ToFloat64(Node* node) {
   VisitRR(this, kMipsCvtDUw, node);
 }
 
 
 void InstructionSelector::VisitChangeFloat64ToInt32(Node* node) {
   VisitRR(this, kMipsTruncWD, node);
 }
 
 
@@ skipping 644 matching lines @@
       IsFp64Mode()) {
     flags |= MachineOperatorBuilder::kFloat64RoundDown |
              MachineOperatorBuilder::kFloat64RoundTruncate;
   }
   return flags;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8