Implemented the RoundUint64ToFloat64 TurboFan operator for x64 and arm64.

src/compiler/typer.cc

Index: src/compiler/typer.cc
diff --git a/src/compiler/typer.cc b/src/compiler/typer.cc
index d6a4a58fa0d89d711d4dc4f7da8732790b34efb9..4dbf4a488851738d1b50fbac823a4a1b4b7a2f9b 100644
--- a/src/compiler/typer.cc
+++ b/src/compiler/typer.cc
@@ -2120,6 +2120,11 @@ Type* Typer::Visitor::TypeRoundInt64ToFloat64(Node* node) {
 }
 
 
+Type* Typer::Visitor::TypeRoundUint64ToFloat64(Node* node) {
+  return Type::Intersect(Type::PlainNumber(), Type::UntaggedFloat64(), zone());
+}
+
+
 Type* Typer::Visitor::TypeBitcastFloat32ToInt32(Node* node) {
   return Type::Number();
 }