[turbofan] Add the RoundInt32ToFloat32 operator to turbofan.

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

Index: src/compiler/arm/instruction-selector-arm.cc
diff --git a/src/compiler/arm/instruction-selector-arm.cc b/src/compiler/arm/instruction-selector-arm.cc
index f3deae7d758f0eee1ecd13ce0c766d7e3146628f..41ad76781a09014b2e181b20e5660985a23ee9f7 100644
--- a/src/compiler/arm/instruction-selector-arm.cc
+++ b/src/compiler/arm/instruction-selector-arm.cc
@@ -921,6 +921,11 @@ void InstructionSelector::VisitChangeFloat32ToFloat64(Node* node) {
 }
 
 
+void InstructionSelector::VisitRoundInt32ToFloat32(Node* node) {
+  VisitRR(this, kArmVcvtF32S32, node);
+}
+
+
 void InstructionSelector::VisitChangeInt32ToFloat64(Node* node) {
   VisitRR(this, kArmVcvtF64S32, node);
 }