Eliminate Smi check when changing from Smi to Integer32

src/arm/lithium-arm.cc

Index: src/arm/lithium-arm.cc
diff --git a/src/arm/lithium-arm.cc b/src/arm/lithium-arm.cc
index ef1cf79ffe1eeec4e25aa90a7328e41a84318472..71916a713638bcebfaf4bf9f1c4378558d8eb595 100644
--- a/src/arm/lithium-arm.cc
+++ b/src/arm/lithium-arm.cc
@@ -1889,10 +1889,14 @@ LInstruction* LChunkBuilder::DoChange(HChange* instr) {
   Representation from = instr->from();
   Representation to = instr->to();
   if (from.IsSmi()) {
-    if (to.IsTagged()) {
+    if (to.IsSmiOrTagged()) {
       LOperand* value = UseRegister(instr->value());
       return DefineSameAsFirst(new(zone()) LDummyUse(value));
     }
+    if (to.IsInteger32()) {
+      LOperand* value = UseRegister(instr->value());
+      return DefineSameAsFirst(new(zone()) LSmiUntag(value, false));
+    }
     from = Representation::Tagged();
   }
   if (from.IsTagged()) {