[turbofan] Added the RoundInt64ToFloat64 instruction to TurboFan.

src/compiler/arm64/instruction-selector-arm64.cc

Index: src/compiler/arm64/instruction-selector-arm64.cc
diff --git a/src/compiler/arm64/instruction-selector-arm64.cc b/src/compiler/arm64/instruction-selector-arm64.cc
index bf7d54dfe3a71ac250ab39e6b72dca0f6fd289f5..da43b417d980fc5f2cc5d59abe3ea69602cdeeab 100644
--- a/src/compiler/arm64/instruction-selector-arm64.cc
+++ b/src/compiler/arm64/instruction-selector-arm64.cc
@@ -1282,6 +1282,11 @@ void InstructionSelector::VisitTruncateInt64ToInt32(Node* node) {
 }
 
 
+void InstructionSelector::VisitRoundInt64ToFloat64(Node* node) {
+  VisitRR(this, kArm64Int64ToFloat64, node);
+}
+
+
 void InstructionSelector::VisitBitcastFloat32ToInt32(Node* node) {
   VisitRR(this, kArm64Float64ExtractLowWord32, node);
 }