Implement set trap for proxies, and revamp class hierarchy in preparation

src/runtime.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 3703 matching lines @@
         Execution::ToString(key, &has_pending_exception);
     if (has_pending_exception) return Failure::Exception();
     name = Handle<String>::cast(converted);
   }
 
   // Check if the name is trivially convertible to an index and get
   // the element if so.
   if (name->AsArrayIndex(&index)) {
     return GetElementOrCharAt(isolate, object, index);
   } else {
-    PropertyAttributes attr;
-    return object->GetProperty(*name, &attr);
+    return object->GetProperty(*name);
   }
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_GetProperty) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 2);
 
   Handle<Object> object = args.at<Object>(0);
   Handle<Object> key = args.at<Object>(1);
@@ skipping 8589 matching lines @@
   } else {
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     isolate->counters()->gc_last_resort_from_js()->Increment();
     isolate->heap()->CollectAllGarbage(false);
   }
 }
 
 
 } }  // namespace v8::internal