Refactor SharedFunctionInfo::IsBuiltin.

src/runtime/runtime-scopes.cc

Index: src/runtime/runtime-scopes.cc
diff --git a/src/runtime/runtime-scopes.cc b/src/runtime/runtime-scopes.cc
index 377799fe047dbc6539463e032028eb4fb561db97..5d7c2cd232f976f5b2322578c0bc5d876193a569 100644
--- a/src/runtime/runtime-scopes.cc
+++ b/src/runtime/runtime-scopes.cc
@@ -670,8 +670,9 @@ RUNTIME_FUNCTION(Runtime_NewScriptContext) {
   // Script contexts have a canonical empty function as their closure, not the
   // anonymous closure containing the global code.  See
   // FullCodeGenerator::PushFunctionArgumentForContextAllocation.
-  Handle<JSFunction> closure(
-      function->shared()->IsBuiltin() ? *function : native_context->closure());
+  Handle<JSFunction> closure(function->shared()->IsUserJavaScript()
+                                 ? native_context->closure()
+                                 : *function);
   Handle<Context> result =
       isolate->factory()->NewScriptContext(closure, scope_info);