[turbofan] Set proper representation for initial arguments length.

src/bootstrapper.cc

Index: src/bootstrapper.cc
diff --git a/src/bootstrapper.cc b/src/bootstrapper.cc
index 57a056e0acaecd5bafa9bf93b09cbc53fa4e9f69..51fde346b13d5f4c0be722b4f02a478fcf05bd96 100644
--- a/src/bootstrapper.cc
+++ b/src/bootstrapper.cc
@@ -3029,13 +3029,13 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
     {  // length
       Descriptor d = Descriptor::DataField(
           factory->length_string(), JSSloppyArgumentsObject::kLengthIndex,
-          DONT_ENUM, Representation::Tagged());
+          DONT_ENUM, Representation::Smi());
       map->AppendDescriptor(&d);
     }
     {  // callee
       Descriptor d = Descriptor::DataField(
           factory->callee_string(), JSSloppyArgumentsObject::kCalleeIndex,
-          DONT_ENUM, Representation::Tagged());
+          DONT_ENUM, Representation::HeapObject());
       map->AppendDescriptor(&d);
     }
     // @@iterator method is added later.
@@ -3086,7 +3086,7 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
     {  // length
       Descriptor d = Descriptor::DataField(
           factory->length_string(), JSStrictArgumentsObject::kLengthIndex,
-          DONT_ENUM, Representation::Tagged());
+          DONT_ENUM, Representation::Smi());
       map->AppendDescriptor(&d);
     }
     {  // callee