[runtime] Add PropertyConstness bit to PropertyDetails.

src/property.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/property.h"
 
 #include "src/field-type.h"
 #include "src/handles-inl.h"
 #include "src/objects-inl.h"
 #include "src/ostreams.h"
 
 namespace v8 {
 namespace internal {
 
 std::ostream& operator<<(std::ostream& os,
                          const PropertyAttributes& attributes) {
   os << "[";
   os << (((attributes & READ_ONLY) == 0) ? "W" : "_");    // writable
   os << (((attributes & DONT_ENUM) == 0) ? "E" : "_");    // enumerable
   os << (((attributes & DONT_DELETE) == 0) ? "C" : "_");  // configurable
   os << "]";
   return os;
 }
 
 Descriptor Descriptor::DataField(Handle<Name> key, int field_index,
                                  PropertyAttributes attributes,
                                  Representation representation) {
-  return DataField(key, field_index, FieldType::Any(key->GetIsolate()),
-                   attributes, representation);
+  return DataField(key, field_index, attributes, kMutable, representation,
+                   FieldType::Any(key->GetIsolate()));
+}
+
+Descriptor Descriptor::DataField(Handle<Name> key, int field_index,
+                                 PropertyAttributes attributes,
+                                 PropertyConstness constness,
+                                 Representation representation,
+                                 Handle<Object> wrapped_field_type) {
+  DCHECK(wrapped_field_type->IsSmi() || wrapped_field_type->IsWeakCell());
+  PropertyDetails details(kData, attributes, kField, constness, representation,
+                          field_index);
+  return Descriptor(key, wrapped_field_type, details);
 }
 
 // Outputs PropertyDetails as a dictionary details.
 void PropertyDetails::PrintAsSlowTo(std::ostream& os) {
   os << "(";
+  if (constness() == kConst) os << "const ";
   os << (kind() == kData ? "data" : "accessor");
   os << ", dictionary_index: " << dictionary_index();
   os << ", attrs: " << attributes() << ")";
 }
 
 // Outputs PropertyDetails as a descriptor array details.
 void PropertyDetails::PrintAsFastTo(std::ostream& os, PrintMode mode) {
   os << "(";
+  if (constness() == kConst) os << "const ";
   os << (kind() == kData ? "data" : "accessor");
   if (location() == kField) {
     os << " field";
     if (mode & kPrintFieldIndex) {
       os << " " << field_index();
     }
     if (mode & kPrintRepresentation) {
       os << ":" << representation().Mnemonic();
     }
   } else {
@@ skipping 15 matching lines @@
     PrintAsSlowTo(os);
   } else {
     PrintAsFastTo(os, PrintMode::kPrintFull);
   }
   os << "\n" << std::flush;
 }
 #endif
 
 }  // namespace internal
 }  // namespace v8