[runtime] Remove specific Descriptor subclasses and add respective factory methods instead.

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/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;
 }
 
-DataDescriptor::DataDescriptor(Handle<Name> key, int field_index,
-                               PropertyAttributes attributes,
-                               Representation representation)
-    : Descriptor(key, FieldType::Any(key->GetIsolate()), attributes, DATA,
-                 representation, field_index) {}
+Descriptor Descriptor::DataField(Handle<Name> key, int field_index,
+                                 PropertyAttributes attributes,
+                                 Representation representation) {
+  return Descriptor(key, FieldType::Any(key->GetIsolate()), attributes, DATA,
+                    representation, field_index);
+}
 
 struct FastPropertyDetails {
   explicit FastPropertyDetails(const PropertyDetails& v) : details(v) {}
   const PropertyDetails details;
 };
 
 
 // Outputs PropertyDetails as a dictionary details.
 std::ostream& operator<<(std::ostream& os, const PropertyDetails& details) {
   os << "(";
@@ skipping 44 matching lines @@
     AccessorPair* pair = AccessorPair::cast(value);
     os << "(get: " << Brief(pair->getter())
        << ", set: " << Brief(pair->setter()) << ") ";
   }
   os << FastPropertyDetails(d.GetDetails());
   return os;
 }
 
 }  // namespace internal
 }  // namespace v8