[turbofan] Set proper representation for initial arguments length.

src/compiler/access-builder.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/access-builder.h"
 
 #include "src/compiler/type-cache.h"
 #include "src/contexts.h"
 #include "src/frames.h"
 #include "src/handles-inl.h"
@@ skipping 698 matching lines @@
                         Type::NonInternal(), MachineType::AnyTagged(),
                         kFullWriteBarrier};
   return access;
 }
 
 
 // static
 FieldAccess AccessBuilder::ForArgumentsLength() {
   FieldAccess access = {kTaggedBase,         JSArgumentsObject::kLengthOffset,
                         Handle<Name>(),      MaybeHandle<Map>(),
-                        Type::NonInternal(), MachineType::AnyTagged(),
-                        kFullWriteBarrier};
+                        Type::SignedSmall(), MachineType::TaggedSigned(),
+                        kNoWriteBarrier};
   return access;
 }
 
 
 // static
 FieldAccess AccessBuilder::ForArgumentsCallee() {
   FieldAccess access = {
       kTaggedBase,         JSSloppyArgumentsObject::kCalleeOffset,
       Handle<Name>(),      MaybeHandle<Map>(),
       Type::NonInternal(), MachineType::AnyTagged(),
@@ skipping 217 matching lines @@
       MaybeHandle<Map>(),
       Type::SignedSmall(),
       MachineType::TaggedSigned(),
       kNoWriteBarrier};
   return access;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8