[turbofan] Use the typer to statically detect Smis.

src/compiler/change-lowering.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/change-lowering.h"
 
 #include "src/code-factory.h"
 #include "src/compiler/diamond.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/linkage.h"
@@ skipping 147 matching lines @@
   return Replace(AllocateHeapNumberWithValue(val, control));
 }
 
 
 Reduction ChangeLowering::ChangeInt32ToTagged(Node* value, Node* control) {
   if (machine()->Is64()) {
     return Replace(graph()->NewNode(
         machine()->Word64Shl(),
         graph()->NewNode(machine()->ChangeInt32ToInt64(), value),
         SmiShiftBitsConstant()));
-  } else if (NodeProperties::GetBounds(value).upper->Is(Type::Signed31())) {
+  } else if (NodeProperties::GetBounds(value).upper->Is(Type::SignedSmall())) {
     return Replace(
         graph()->NewNode(machine()->WordShl(), value, SmiShiftBitsConstant()));
   }
 
   Node* add = graph()->NewNode(machine()->Int32AddWithOverflow(), value, value);
   Node* ovf = graph()->NewNode(common()->Projection(1), add);
 
   Diamond d(graph(), common(), ovf, BranchHint::kFalse);
   d.Chain(control);
   return Replace(
@@ skipping 103 matching lines @@
 }
 
 
 MachineOperatorBuilder* ChangeLowering::machine() const {
   return jsgraph()->machine();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8