Store JSGlobalProxy's identity hash directly on the proxy itself

src/runtime.cc

Index: src/runtime.cc
diff --git a/src/runtime.cc b/src/runtime.cc
index 1fa6da8312ba780ad5ef7f6f16d07e4dec2a4059..02509d79548b9e5dd028aeec9f87b20816107be3 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -14867,6 +14867,18 @@ RUNTIME_FUNCTION(Runtime_ObservationWeakMapCreate) {
 }
 
 
+RUNTIME_FUNCTION(Runtime_UnwrapGlobalProxy) {
+  SealHandleScope shs(isolate);
+  ASSERT(args.length() == 1);
+  Object* object = args[0];
+  if (object->IsJSGlobalProxy()) {
+    object = object->GetPrototype(isolate);
+    if (object->IsNull()) return isolate->heap()->undefined_value();
+  }
+  return object;
+}
+
+
 RUNTIME_FUNCTION(Runtime_IsAccessAllowedForObserver) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 3);