Revert of 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 6c9eb3171246f78769307c34b36b429af4376c4d..0c037db307a60ca994da643e9a2554b462654ced 100644
--- a/src/runtime/runtime-scopes.cc
+++ b/src/runtime/runtime-scopes.cc
@@ -670,9 +670,8 @@
   // 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()->IsUserJavaScript()
-                                 ? native_context->closure()
-                                 : *function);
+  Handle<JSFunction> closure(
+      function->shared()->IsBuiltin() ? *function : native_context->closure());
   Handle<Context> result =
       isolate->factory()->NewScriptContext(closure, scope_info);