[turbofan] Implemented the optional Float32RoundTiesEven operator.

src/compiler/ia32/instruction-selector-ia32.cc

Index: src/compiler/ia32/instruction-selector-ia32.cc
diff --git a/src/compiler/ia32/instruction-selector-ia32.cc b/src/compiler/ia32/instruction-selector-ia32.cc
index f298c01f1d43cada350d3a4b7d74208a119081dc..db50c776ee2f9006de5f460294f04bf8e9b7dcd5 100644
--- a/src/compiler/ia32/instruction-selector-ia32.cc
+++ b/src/compiler/ia32/instruction-selector-ia32.cc
@@ -886,6 +886,11 @@ 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));
 }
@@ -1305,6 +1310,7 @@ InstructionSelector::SupportedMachineOperatorFlags() {
              MachineOperatorBuilder::kFloat64RoundUp |
              MachineOperatorBuilder::kFloat32RoundTruncate |
              MachineOperatorBuilder::kFloat64RoundTruncate |
+             MachineOperatorBuilder::kFloat32RoundTiesEven |
              MachineOperatorBuilder::kFloat64RoundTiesEven;
   }
   return flags;