[turbofan] Add the RoundInt32ToFloat32 operator to turbofan.

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 090645212e9f16928258f3ce0fa1104dd0fd83ad..ecc05e0d2fe2b17e6a080b98233e30373ad5ecb4 100644
--- a/src/compiler/ia32/instruction-selector-ia32.cc
+++ b/src/compiler/ia32/instruction-selector-ia32.cc
@@ -695,6 +695,11 @@ void InstructionSelector::VisitChangeFloat32ToFloat64(Node* node) {
 }
 
 
+void InstructionSelector::VisitRoundInt32ToFloat32(Node* node) {
+  VisitRO(this, node, kSSEInt32ToFloat32);
+}
+
+
 void InstructionSelector::VisitChangeInt32ToFloat64(Node* node) {
   VisitRO(this, node, kSSEInt32ToFloat64);
 }