MIPS: [turbofan] Add RoundUint32ToFloat32 operator to Turbofan.

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 c1a023d36d5a89cbeaede977c8cb751bf2ce18e0..44a5470aca12dc22bbe189510022c4cc71719d35 100644
--- a/src/compiler/mips64/instruction-selector-mips64.cc
+++ b/src/compiler/mips64/instruction-selector-mips64.cc
@@ -830,7 +830,7 @@ void InstructionSelector::VisitRoundInt32ToFloat32(Node* node) {
 
 
 void InstructionSelector::VisitRoundUint32ToFloat32(Node* node) {
-  UNIMPLEMENTED();
+  VisitRR(this, kMips64CvtSUw, node);
 }