Implement `in' for proxies.

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 4297 matching lines @@
     }
   }
   return isolate->heap()->false_value();
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_HasProperty) {
   NoHandleAllocation na;
   ASSERT(args.length() == 2);
 
-  // Only JS objects can have properties.
-  if (args[0]->IsJSObject()) {
-    JSObject* object = JSObject::cast(args[0]);
+  // Only JS receivers can have properties.
+  if (args[0]->IsJSReceiver()) {
+    JSReceiver* receiver = JSReceiver::cast(args[0]);
     CONVERT_CHECKED(String, key, args[1]);
-    if (object->HasProperty(key)) return isolate->heap()->true_value();
+    if (receiver->HasProperty(key)) return isolate->heap()->true_value();
   }
   return isolate->heap()->false_value();
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_HasElement) {
   NoHandleAllocation na;
   ASSERT(args.length() == 2);
 
   // Only JS objects can have elements.
@@ skipping 8362 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