[turbofan] Added the RoundInt64ToFloat64 instruction to TurboFan.

src/compiler/mips/instruction-selector-mips.cc

Index: src/compiler/mips/instruction-selector-mips.cc
diff --git a/src/compiler/mips/instruction-selector-mips.cc b/src/compiler/mips/instruction-selector-mips.cc
index 602b9f9b1ca6a1d5f74a78ff98321447f3c9cdec..42c3c4b3016f1fd5b889d434d882b0a22448a99f 100644
--- a/src/compiler/mips/instruction-selector-mips.cc
+++ b/src/compiler/mips/instruction-selector-mips.cc
@@ -376,6 +376,11 @@ void InstructionSelector::VisitChangeInt32ToFloat64(Node* node) {
 }
 
 
+void InstructionSelector::VisitRoundInt64ToFloat64(Node* node) {
+  UNIMPLEMENTED();
+}
+
+
 void InstructionSelector::VisitChangeUint32ToFloat64(Node* node) {
   VisitRR(this, kMipsCvtDUw, node);
 }