Fix MUST_USE_RESULT warning.

R=dcarney@chromium.org

Review URL: https://codereview.chromium.org/228203003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@20561 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/objects.cc

@@ -3799,7 +3799,7 @@ PropertyAttributes JSProxy::GetPropertyAttributeWithHandler(
     Handle<Object> args[] = { handler, trap, name };
     Handle<Object> error = isolate->factory()->NewTypeError(
         "proxy_prop_not_configurable", HandleVector(args, ARRAY_SIZE(args)));
-    isolate->Throw<Object>(error);
+    isolate->Throw(*error);
     return NONE;
   }