[turbofan] Implemented the optional Float32RoundTiesEven operator.

src/compiler/x87/instruction-selector-x87.cc

Index: src/compiler/x87/instruction-selector-x87.cc
diff --git a/src/compiler/x87/instruction-selector-x87.cc b/src/compiler/x87/instruction-selector-x87.cc
index 52dfbff3eeaef46c79b682d8667a240d8d4b3dc2..3c06979dc0987697f00fe12f43a50384cd7d32d1 100644
--- a/src/compiler/x87/instruction-selector-x87.cc
+++ b/src/compiler/x87/instruction-selector-x87.cc
@@ -875,6 +875,11 @@ void InstructionSelector::VisitFloat64RoundTiesAway(Node* node) {
 }
 
 
+void InstructionSelector::VisitFloat32RoundTiesEven(Node* node) {
+  UNREACHABLE();
+}
+
+
 void InstructionSelector::VisitFloat64RoundTiesEven(Node* node) {
   UNREACHABLE();
 }