[proxies] Implement Proxy.revocable.

src/runtime/runtime-proxy.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/runtime/runtime-utils.h"
 
 #include "src/arguments.h"
 #include "src/factory.h"
 #include "src/objects-inl.h"
 
@@ skipping 47 matching lines @@
 }
 
 
 RUNTIME_FUNCTION(Runtime_GetConstructTrap) {
   SealHandleScope shs(isolate);
   DCHECK(args.length() == 1);
   CONVERT_ARG_CHECKED(JSFunctionProxy, proxy, 0);
   return proxy->construct_trap();
 }
 
+
+RUNTIME_FUNCTION(Runtime_RevokeProxy) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(JSProxy, proxy, 0);
+  JSProxy::Revoke(proxy);
+  return isolate->heap()->undefined_value();
+}
+
+
 }  // namespace internal
 }  // namespace v8