[turbofan] Address a couple of Type-related TODOs.

src/compiler/js-native-context-specialization.cc

 // Copyright 2015 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/js-native-context-specialization.h"
 
 #include "src/accessors.h"
 #include "src/code-factory.h"
 #include "src/compilation-dependencies.h"
 #include "src/compiler/access-builder.h"
@@ skipping 1262 matching lines @@
                                         length, effect, control);
     }
 
     // Compute the element access.
     Type* element_type = Type::NonInternal();
     MachineType element_machine_type = MachineType::AnyTagged();
     if (IsFastDoubleElementsKind(elements_kind)) {
       element_type = Type::Number();
       element_machine_type = MachineType::Float64();
     } else if (IsFastSmiElementsKind(elements_kind)) {
-      element_type = type_cache_.kSmi;
+      element_type = Type::SignedSmall();
       element_machine_type = MachineType::TaggedSigned();
     }
     ElementAccess element_access = {kTaggedBase, FixedArray::kHeaderSize,
                                     element_type, element_machine_type,
                                     kFullWriteBarrier};
 
     // Access the actual element.
     if (access_mode == AccessMode::kLoad) {
       // Compute the real element access type, which includes the hole in case
       // of holey backing stores.
@@ skipping 323 matching lines @@
   return jsgraph()->javascript();
 }
 
 SimplifiedOperatorBuilder* JSNativeContextSpecialization::simplified() const {
   return jsgraph()->simplified();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8