Mark single-argument inline constructors as 'explicit'.

src/heap.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 3213 matching lines @@
         StringDictionary::Allocate(
             map->NumberOfDescribedProperties() * 2 + initial_size);
     if (!maybe_obj->ToObject(&obj)) return maybe_obj;
   }
   StringDictionary* dictionary = StringDictionary::cast(obj);
 
   // The global object might be created from an object template with accessors.
   // Fill these accessors into the dictionary.
   DescriptorArray* descs = map->instance_descriptors();
   for (int i = 0; i < descs->number_of_descriptors(); i++) {
-    PropertyDetails details = descs->GetDetails(i);
+    PropertyDetails details(descs->GetDetails(i));
     ASSERT(details.type() == CALLBACKS);  // Only accessors are expected.
     PropertyDetails d =
         PropertyDetails(details.attributes(), CALLBACKS, details.index());
     Object* value = descs->GetCallbacksObject(i);
     { MaybeObject* maybe_value = AllocateJSGlobalPropertyCell(value);
       if (!maybe_value->ToObject(&value)) return maybe_value;
     }
 
     Object* result;
     { MaybeObject* maybe_result = dictionary->Add(descs->GetKey(i), value, d);
@@ skipping 2602 matching lines @@
 }
 
 
 void ExternalStringTable::TearDown() {
   new_space_strings_.Free();
   old_space_strings_.Free();
 }
 
 
 } }  // namespace v8::internal