Implemented the RoundUint64ToFloat64 TurboFan operator for x64 and arm64.

src/compiler/instruction-selector.cc

Index: src/compiler/instruction-selector.cc
diff --git a/src/compiler/instruction-selector.cc b/src/compiler/instruction-selector.cc
index eac5571e9c4b8ae1424aab36d9690efb941a5db0..969abb094481c07ac737e356750724b35fd7f568 100644
--- a/src/compiler/instruction-selector.cc
+++ b/src/compiler/instruction-selector.cc
@@ -822,6 +822,8 @@ void InstructionSelector::VisitNode(Node* node) {
       return MarkAsFloat64(node), VisitRoundInt64ToFloat64(node);
     case IrOpcode::kBitcastFloat32ToInt32:
       return MarkAsWord32(node), VisitBitcastFloat32ToInt32(node);
+    case IrOpcode::kRoundUint64ToFloat64:
+      return MarkAsFloat64(node), VisitRoundUint64ToFloat64(node);
     case IrOpcode::kBitcastFloat64ToInt64:
       return MarkAsWord64(node), VisitBitcastFloat64ToInt64(node);
     case IrOpcode::kBitcastInt32ToFloat32:
@@ -1053,6 +1055,11 @@ void InstructionSelector::VisitRoundInt64ToFloat64(Node* node) {
 }
 
 
+void InstructionSelector::VisitRoundUint64ToFloat64(Node* node) {
+  UNIMPLEMENTED();
+}
+
+
 void InstructionSelector::VisitBitcastFloat64ToInt64(Node* node) {
   UNIMPLEMENTED();
 }