Implemented the RoundUint64ToFloat64 TurboFan operator for x64 and arm64.

src/compiler/mips64/instruction-selector-mips64.cc

Index: src/compiler/mips64/instruction-selector-mips64.cc
diff --git a/src/compiler/mips64/instruction-selector-mips64.cc b/src/compiler/mips64/instruction-selector-mips64.cc
index c62d0ef37241aa7a45e0a9663a9fa477289f300a..83913419cd997743ea7dc7fad6fc3a3ef1ff6d3d 100644
--- a/src/compiler/mips64/instruction-selector-mips64.cc
+++ b/src/compiler/mips64/instruction-selector-mips64.cc
@@ -627,6 +627,11 @@ void InstructionSelector::VisitRoundInt64ToFloat64(Node* node) {
 }
 
 
+void InstructionSelector::VisitRoundUint64ToFloat64(Node* node) {
+  UNIMPLEMENTED();
+}
+
+
 void InstructionSelector::VisitBitcastFloat32ToInt32(Node* node) {
   VisitRR(this, kMips64Float64ExtractLowWord32, node);
 }