[turbofan] Add the RoundInt32ToFloat32 operator to turbofan.

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

Index: src/compiler/ppc/instruction-selector-ppc.cc
diff --git a/src/compiler/ppc/instruction-selector-ppc.cc b/src/compiler/ppc/instruction-selector-ppc.cc
index f6ebbdf5d6ab249a47cc1cc5469b0a139643f8b5..b2f4c06a1eb175af2acbba5404b2eb1eeca9c94c 100644
--- a/src/compiler/ppc/instruction-selector-ppc.cc
+++ b/src/compiler/ppc/instruction-selector-ppc.cc
@@ -940,6 +940,11 @@ void InstructionSelector::VisitChangeFloat32ToFloat64(Node* node) {
 }
 
 
+void InstructionSelector::VisitRoundInt32ToFloat32(Node* node) {
+  VisitRR(this, kPPC_Int32ToFloat32, node);
+}
+
+
 void InstructionSelector::VisitChangeInt32ToFloat64(Node* node) {
   VisitRR(this, kPPC_Int32ToDouble, node);
 }