[turbofan] Implemented the optional Float32RoundTiesEven operator.

src/compiler/x64/instruction-selector-x64.cc

Index: src/compiler/x64/instruction-selector-x64.cc
diff --git a/src/compiler/x64/instruction-selector-x64.cc b/src/compiler/x64/instruction-selector-x64.cc
index 44024094bc47ba12769a43e5e319060cf3adf428..e03e52bb7195a49b310ffad00e1fd985bd6b25b3 100644
--- a/src/compiler/x64/instruction-selector-x64.cc
+++ b/src/compiler/x64/instruction-selector-x64.cc
@@ -1173,6 +1173,11 @@ void InstructionSelector::VisitFloat64RoundTiesAway(Node* node) {
 }
 
 
+void InstructionSelector::VisitFloat32RoundTiesEven(Node* node) {
+  VisitRR(this, node, kSSEFloat32Round | MiscField::encode(kRoundToNearest));
+}
+
+
 void InstructionSelector::VisitFloat64RoundTiesEven(Node* node) {
   VisitRR(this, node, kSSEFloat64Round | MiscField::encode(kRoundToNearest));
 }
@@ -1712,6 +1717,7 @@ InstructionSelector::SupportedMachineOperatorFlags() {
              MachineOperatorBuilder::kFloat64RoundUp |
              MachineOperatorBuilder::kFloat32RoundTruncate |
              MachineOperatorBuilder::kFloat64RoundTruncate |
+             MachineOperatorBuilder::kFloat32RoundTiesEven |
              MachineOperatorBuilder::kFloat64RoundTiesEven;
   }
   return flags;