Implement sealing, freezing, and related functions for proxies.

src/heap.h

Index: src/heap.h
diff --git a/src/heap.h b/src/heap.h
index d90a681d436794173bee8680c17c3bb7df6177f3..3211dfdc70419eb9569766e457925b8ae3c47f30 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -441,6 +441,12 @@ class Heap {
   MUST_USE_RESULT MaybeObject* AllocateJSProxy(Object* handler,
                                                Object* prototype);
 
+  // Reinitialize a JSReceiver into an (empty) JSObject.  The receiver
+  // must have the same size as an empty object.  The object is reinitialized
+  // and behaves as an object that has been freshly allocated.
+  MUST_USE_RESULT MaybeObject* ReinitializeJSReceiverAsJSObject(

[Mads Ager (chromium), 2011/07/17 10:43:47]

JSReceiver -> JSProxy

We don't need this operation for anything else and the current implementation
restrictions on the size of the input means that it will not work for much else.
Let's reflect that in the type of the input?

[rossberg, 2011/07/18 10:53:53]

Done.

+      JSReceiver* object);
+
   // Reinitialize an JSGlobalProxy based on a constructor.  The object
   // must have the same size as objects allocated using the
   // constructor.  The object is reinitialized and behaves as an